How to find variable type in Rust example

This tutorial shows how to get the variable datatype in Rust “Occasionally, it’s necessary to determine the variable type to validate assigned data.

Rust gets Variable Type

There are various ways to obtain the datatype of a variable in Rust:

Using the std::any::type_name function.
Using the std::intrinsics::type_name function.

std::any::type_name function to get type of variable:

The std::any::type_name function returns the type of a variable as a string slice.

It is available in Rust standard library std:any that provides simple and readable methods to get the type of a variable. In the example below, the program prints the types of the following variables:

Integer types
Boolean type
String
flat
character
tuples
array
vector

fn main() {
    let str = "test";
    let number = 11;
    let price= 21.11;
    let f1: f32 = 12.01;
    let b = true;
    let charcter = 'z';
    let tuptype: (i32, f64, u8) = (10, 2.9, 1);
    let arraytype = [1, 2, 3, 4, 5];
    let vectortype = vec![1, 2, 3];

    print_variable_type(&str);
    print_variable_type(&number);
    print_variable_type(&price);
    print_variable_type(&f1);
    print_variable_type(&b);
    print_variable_type(&charcter);
    print_variable_type(&tuptype);
    print_variable_type(&arraytype);
    print_variable_type(&vectortype);

}
fn print_variable_type<K>(_: &K) {
    println!("{}", std::any::type_name::<K>())
}

Output:

&str
i32
f64
f32
bool
char
(i32, f64, u8)
[i32; 5]
alloc::vec::Vec<i32>

Using std::intrinsics::type_name Function:

Another approach to obtain the variable type is by using the std::intrinsics::type_name function. However, note that this function is part of an unstable feature and may not work in a stable release.

#![feature(core_intrinsics)]

fn main() {
    let str = "test";
    let number = 11;
    let price= 21.11;
    let f1: f32 = 12.01;
    let b = true;
    let charcter = 'z';
    let tuptype: (i32, f64, u8) = (10, 2.9, 1);
    let arraytype = [1, 2, 3, 4, 5];
    let vectortype = vec![1, 2, 3];


    print_variable_type(&str);
    print_variable_type(&number);
    print_variable_type(&price);
    print_variable_type(&f1);
    print_variable_type(&b);
    print_variable_type(&charcter);
    print_variable_type(&tuptype);
    print_variable_type(&arraytype);
    print_variable_type(&vectortype);

}
fn print_variable_type<K>(_: &K) {
    println!("{}", unsafe { std::intrinsics::type_name::<K>() });

}

Conclusion

In summary, understanding how to retrieve variable types in Rust is essential for developers to write efficient code. By utilizing these two methods, one can debug code effectively and prevent errors.

How to find variable type in Rust example

#Rust gets Variable Type

#Conclusion

Rust gets Variable Type

Conclusion