If expression in Rust

When writing a computer program, we often want it to execute different actions for different scenarios and conditions.

In Rust, this is where the if expression comes in. Let’s have a look at what the if expression is.

Syntax

The form of an if expression is a condition, followed by a block of code; there can be an else expression with this block of code. See the syntax below for a basic if expression in Rust:

if expression {
    /* block of code in case expression
       is TRUE */
} else {
    /* block of code in case expression
       is FALSE */
}

Code

Let’s consider a simple example where we have to determine which number is greater out of the integer variables a and b. The code snippet below illustrates how this can be done using an if expression in Rust:

fn main() {

  let a = 50;

  let b = 20;



  if a > b {

    // condition is TRUE

    println!("a is greater than b")

  } else {

    // condition is FALSE

    println!("a is less than b")

  }

}

The code above follows the process flow below:

if-else Flowchart
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