# serde_json::Number - Rust
API documentation for the Rust `Number` struct in crate `serde_json`.
Keywords: rust, rustlang, rust-lang, Number

# Struct serde_json::Number [−] [src]

    pub struct Number { /* fields omitted */ }

Represents a JSON number, whether integer or floating point.

## Implementations

### `impl Number` [src]

#### `pub fn is_i64(&self) -> bool` [src]

Returns true if the `Number` is an integer between `i64::MIN` and `i64::MAX`.

For any Number on which `is_i64` returns true, `as_i64` is guaranteed to return the integer value.

    let big = i64::max_value() as u64 + 10;
    let v = json!({ "a": 64, "b": big, "c": 256.0 });

    assert!(v["a"].is_i64());

    // Greater than i64::MAX.
    assert!(!v["b"].is_i64());

    // Numbers with a decimal point are not considered integers.
    assert!(!v["c"].is_i64());

#### `pub fn is_u64(&self) -> bool` [src]

Returns true if the `Number` is an integer between zero and `u64::MAX`.

For any Number on which `is_u64` returns true, `as_u64` is guaranteed to return the integer value.

    let v = json!({ "a": 64, "b": -64, "c": 256.0 });

    assert!(v["a"].is_u64());

    // Negative integer.
    assert!(!v["b"].is_u64());

    // Numbers with a decimal point are not considered integers.
    assert!(!v["c"].is_u64());

#### `pub fn is_f64(&self) -> bool` [src]

Returns true if the `Number` can be represented by f64.

For any Number on which `is_f64` returns true, `as_f64` is guaranteed to return the floating point value.

Currently this function returns true if and only if both `is_i64` and `is_u64` return false but this is not a guarantee in the future.

    let v = json!({ "a": 256.0, "b": 64, "c": -64 });

    assert!(v["a"].is_f64());

    // Integers.
    assert!(!v["b"].is_f64());
    assert!(!v["c"].is_f64());

#### `pub fn as_i64(&self) -> Option<i64>` [src]

If the `Number` is an integer, represent it as i64 if possible. Returns None otherwise.

    let big = i64::max_value() as u64 + 10;
    let v = json!({ "a": 64, "b": big, "c": 256.0 });

    assert_eq!(v["a"].as_i64(), Some(64));
    assert_eq!(v["b"].as_i64(), None);
    assert_eq!(v["c"].as_i64(), None);

#### `pub fn as_u64(&self) -> Option<u64>` [src]

If the `Number` is an integer, represent it as u64 if possible. Returns None otherwise.

    let v = json!({ "a": 64, "b": -64, "c": 256.0 });

    assert_eq!(v["a"].as_u64(), Some(64));
    assert_eq!(v["b"].as_u64(), None);
    assert_eq!(v["c"].as_u64(), None);

#### `pub fn as_f64(&self) -> Option<f64>` [src]

Represents the number as f64 if possible. Returns None otherwise.

    let v = json!({ "a": 256.0, "b": 64, "c": -64 });

    assert_eq!(v["a"].as_f64(), Some(256.0));
    assert_eq!(v["b"].as_f64(), Some(64.0));
    assert_eq!(v["c"].as_f64(), Some(-64.0));

#### `pub fn from_f64(f: f64) -> Option<Number>` [src]

Converts a finite `f64` to a `Number`. Infinite or NaN values are not JSON numbers.

    assert!(Number::from_f64(256.0).is_some());

    assert!(Number::from_f64(f64::NAN).is_none());

## Trait Implementations

### `impl Clone for Number` [src]

#### `fn clone(&self) -> Number` [src]

Returns a copy of the value. Read more

#### `pub fn clone_from(&mut self, source: &Self)`1.0.0 [src]

Performs copy-assignment from `source`. Read more

### `impl Debug for Number` [src]

#### `fn fmt(&self, formatter: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl<'de> Deserialize<'de> for Number` [src]

#### `fn deserialize<D>(deserializer: D) -> Result<Number, D::Error> where
D: Deserializer<'de>,` [src]

Deserialize this value from the given Serde deserializer. Read more

### `impl<'de> Deserializer<'de> for Number` [src]

#### `type Error = Error`

The error type that can be returned if some error occurs during deserialization. Read more

#### `fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Require the `Deserializer` to figure out how to drive the visitor based on what data type is in the input. Read more

#### `fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i8` value.

#### `fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i16` value.

#### `fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i32` value.

#### `fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i64` value.

#### `fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u8` value.

#### `fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u16` value.

#### `fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u32` value.

#### `fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u64` value.

#### `fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `f32` value.

#### `fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `f64` value.

#### `fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i128` value. Read more

#### `fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `u128` value. Read more

#### `fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `bool` value.

#### `fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `char` value.

#### `fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a string value and does not benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a string value and would benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a byte array and does not benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a byte array and would benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an optional value. Read more

#### `fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a unit value.

#### `fn deserialize_unit_struct<V>(
self,
name: &'static str,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a unit struct with a particular name. Read more

#### `fn deserialize_newtype_struct<V>(
self,
name: &'static str,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a newtype struct with a particular name. Read more

#### `fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a sequence of values.

#### `fn deserialize_tuple<V>(
self,
len: usize,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a sequence of values and knows how many values there are without looking at the serialized data. Read more

#### `fn deserialize_tuple_struct<V>(
self,
name: &'static str,
len: usize,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a tuple struct with a particular name and number of fields. Read more

#### `fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a map of key-value pairs.

#### `fn deserialize_struct<V>(
self,
name: &'static str,
fields: &'static [&'static str],
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a struct with a particular name and fields. Read more

#### `fn deserialize_enum<V>(
self,
name: &'static str,
variants: &'static [&'static str],
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an enum value with a particular name and possible variants. Read more

#### `fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting the name of a struct field or the discriminant of an enum variant. Read more

#### `fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type needs to deserialize a value whose type doesn't matter because it is ignored. Read more

#### `pub fn is_human_readable(&self) -> bool` [src]

Determine whether `Deserialize` implementations should expect to deserialize their human-readable form. Read more

### `impl<'de, 'a> Deserializer<'de> for &'a Number` [src]

#### `type Error = Error`

The error type that can be returned if some error occurs during deserialization. Read more

#### `fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Require the `Deserializer` to figure out how to drive the visitor based on what data type is in the input. Read more

#### `fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i8` value.

#### `fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i16` value.

#### `fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i32` value.

#### `fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i64` value.

#### `fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u8` value.

#### `fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u16` value.

#### `fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u32` value.

#### `fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `u64` value.

#### `fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `f32` value.

#### `fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `f64` value.

#### `fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `i128` value. Read more

#### `fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an `u128` value. Read more

#### `fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `bool` value.

#### `fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a `char` value.

#### `fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a string value and does not benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a string value and would benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a byte array and does not benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a byte array and would benefit from taking ownership of buffered data owned by the `Deserializer`. Read more

#### `fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an optional value. Read more

#### `fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a unit value.

#### `fn deserialize_unit_struct<V>(
self,
name: &'static str,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a unit struct with a particular name. Read more

#### `fn deserialize_newtype_struct<V>(
self,
name: &'static str,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a newtype struct with a particular name. Read more

#### `fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a sequence of values.

#### `fn deserialize_tuple<V>(
self,
len: usize,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a sequence of values and knows how many values there are without looking at the serialized data. Read more

#### `fn deserialize_tuple_struct<V>(
self,
name: &'static str,
len: usize,
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a tuple struct with a particular name and number of fields. Read more

#### `fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a map of key-value pairs.

#### `fn deserialize_struct<V>(
self,
name: &'static str,
fields: &'static [&'static str],
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting a struct with a particular name and fields. Read more

#### `fn deserialize_enum<V>(
self,
name: &'static str,
variants: &'static [&'static str],
visitor: V
) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting an enum value with a particular name and possible variants. Read more

#### `fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type is expecting the name of a struct field or the discriminant of an enum variant. Read more

#### `fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> where
V: Visitor<'de>,` [src]

Hint that the `Deserialize` type needs to deserialize a value whose type doesn't matter because it is ignored. Read more

#### `pub fn is_human_readable(&self) -> bool` [src]

Determine whether `Deserialize` implementations should expect to deserialize their human-readable form. Read more

### `impl Display for Number` [src]

#### `fn fmt(&self, formatter: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl Eq for Number` [src]

### `impl From<Number> for Value` [src]

#### `fn from(f: Number) -> Self` [src]

Convert `Number` to `Value`

# Examples

    use serde_json::{Number, Value};

    let n = Number::from(7);
    let x: Value = n.into();

### `impl From<i16> for Number` [src]

#### `fn from(i: i16) -> Self` [src]

Performs the conversion.

### `impl From<i32> for Number` [src]

#### `fn from(i: i32) -> Self` [src]

Performs the conversion.

### `impl From<i64> for Number` [src]

#### `fn from(i: i64) -> Self` [src]

Performs the conversion.

### `impl From<i8> for Number` [src]

#### `fn from(i: i8) -> Self` [src]

Performs the conversion.

### `impl From<isize> for Number` [src]

#### `fn from(i: isize) -> Self` [src]

Performs the conversion.

### `impl From<u16> for Number` [src]

#### `fn from(u: u16) -> Self` [src]

Performs the conversion.

### `impl From<u32> for Number` [src]

#### `fn from(u: u32) -> Self` [src]

Performs the conversion.

### `impl From<u64> for Number` [src]

#### `fn from(u: u64) -> Self` [src]

Performs the conversion.

### `impl From<u8> for Number` [src]

#### `fn from(u: u8) -> Self` [src]

Performs the conversion.

### `impl From<usize> for Number` [src]

#### `fn from(u: usize) -> Self` [src]

Performs the conversion.

### `impl FromStr for Number` [src]

#### `type Err = Error`

The associated error which can be returned from parsing.

#### `fn from_str(s: &str) -> Result<Self, Self::Err>` [src]

Parses a string `s` to return a value of this type. Read more

### `impl PartialEq<Number> for Number` [src]

#### `fn eq(&self, other: &Number) -> bool` [src]

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Number) -> bool` [src]

This method tests for `!=`.

### `impl Serialize for Number` [src]

#### `fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
S: Serializer,` [src]

Serialize this value into the given Serde serializer. Read more

### `impl StructuralEq for Number` [src]

### `impl StructuralPartialEq for Number` [src]

## Auto Trait Implementations

### `impl RefUnwindSafe for Number` [src]

### `impl Send for Number` [src]

### `impl Sync for Number` [src]

### `impl Unpin for Number` [src]

### `impl UnwindSafe for Number` [src]

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &Tⓘ

### Notable traits for &'_ mut R

`impl<'_, R> Read for &'_ mut R where
R: Read + ?Sized, impl<'_, W> Write for &'_ mut W where
W: Write + ?Sized, impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;`
` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut Tⓘ

### Notable traits for &'_ mut R

`impl<'_, R> Read for &'_ mut R where
R: Read + ?Sized, impl<'_, W> Write for &'_ mut W where
W: Write + ?Sized, impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;`
` [src]

Mutably borrows from an owned value. Read more

### `impl<T> DeserializeOwned for T where
T: for<'de> Deserialize<'de>,` [src]

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `pub fn to_owned(&self) -> T` [src]

Creates owned data from borrowed data, usually by cloning. Read more

#### `pub fn clone_into(&self, target: &mut T)` [src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into`)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `impl<T> ToString for T where
T: Display + ?Sized,` [src]

#### `pub default fn to_string(&self) -> String` [src]

Converts the given value to a `String`. Read more

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.