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Rust program to read a float number from the user

Here, we are going to learn how to read a float number from the user in Rust programming language?
Submitted by Nidhi, on September 22, 2021

Problem Solution:

Here, we will read a floating-point number from the user and print the input value.

Program/Source Code:

The source code to read an integer number from the user is given below. The given program is compiled and executed successfully.

// Rust program to read a float number 
// from the user

use std::io;

fn main() {
    let mut num:f32=0.0;
    let mut input = String::new();
    
    println!("Enter number: ");
    io::stdin().read_line(&mut input).expect("Not a valid string");
    num = input.trim().parse().expect("Not a valid number");
    
    println!("Number is: {}",num);
}

Output:

RUN 1:
Enter number: 
123.45
Number is: 123.45

RUN 2:
Enter number: 
Hello
thread 'main' panicked at 
'Not a valid number: ParseFloatError { kind: Invalid }', 
src/libcore/result.rs:1084:5
note: run with `RUST_BACKTRACE=1` environment variable 
to display a backtrace.

Explanation:

Here, we created a 32-bit floating-point variable num and then read the value for num from the user using the read_line() function and printed the result.

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