If in Rust 1.55

In Rust, if is used to create conditional expressions that evaluate to either true or false. The general syntax of the if statement is:

if condition {
    // code to execute if the condition is true
} else {
    // code to execute if the condition is false
}

Here's an example:

fn main() {
    let x = 10;
    if x == 10 {
        println!("x is equal to 10");
    } else {
        println!("x is not equal to 10");
    }
}

This code sets the variable x to 10 and then checks if x is equal to 10 using the if statement. If it is, the program prints "x is equal to 10". If it's not, the program prints "x is not equal to 10".

You can also use if statements as expressions, like this:

fn main() {
    let x = 10;
    let y = if x == 10 { 5 } else { 15 };
    println!("y is {}", y);
}

In this example, the y variable is assigned a value based on the result of the if statement. If x is equal to 10, y is assigned the value 5. Otherwise, y is assigned the value 15. The program then prints the value of y.

Keep in mind that Rust requires that you include parentheses around the condition, like this:

if (condition) {
    // code to execute if the condition is true
}

This helps make the code easier to read and understand.