Trusted answers to developer questions
Trusted Answers to Developer Questions

Related Tags


What are scalar data types in Rust?

Educative Answers Team

Rust has two main sets of data types for variables: scalar and compound.


Scalar variables are those that can store a single value at a time. There are four scalar data types in Rust.

1. Integer

An integer is a numerical value that does not have a fractional part. An integer can be signed or unsigned. A signed integer (i) can store a negative or a positive value, whereas an unsigned integer (u) can only store positive values. The number of bits used by an integer is explicitly mentioned and is a part of the data type’s name. For example, a variable of type i8 is a signed integer that uses 8 bits.

isize and usize are two special types of integers that are 32-bits or 64-bits depending on the architecture of the CPU.

svg viewer
Variants of a scalar integer in Rust

When no size is explicitly mentioned, i32 is used by default. For example:

let x = 1; // Equivalent to x: i32 = 1;
let y: u64 = 12 // u64

2. Floating-point

Rust offers floating-point types f32(32-bit size) and f64(64 bit-size) to store numbers that have a decimal value. If no size is explicitly mentioned, f64 is used by default:

let x = 1.0; // f64
let y: f32 = 12.5; // f32

3. Boolean

Similar to other languages, Rust has a boolean data type that can store either true or false as its value. The bool keyword is used to specify this scalar data type. A value of true or false can also be stored in a variable without using this keyword:

let b = true; // Equivalent to b: bool = true;

4. Character

In addition to strings, Rust also supports a character data type. Unlike most other programming languages, a character in Rust has a size of 4 bytes instead of 1, and it represents a Unicode Scalar Value meaning that it can store more than just an alphabet (Japanese characters, emojis, accented letters, etc.). A char value is stored using single quotes:

let x = 'R';


Copyright ©2022 Educative, Inc. All rights reserved

View all Courses

Keep Exploring