Conditionals

Conditional statements in Rust allow the control of flow in program based on certain conditions. Rust provides support for conditional statements that include if, else if and else statements. Unlike many programming languages, the condition is not enclosed by parentheses.

If Statement

The if statement is used to execute a block of code if the evaluating condition is true.

Syntax

if condition {
  // Code goes here
}

Example

let number = 15;

if number > 10 {
  println!("This code will be executed.");
}

Else If Statement

The else if statement ladder is used to evaluate multiple conditions after the initial if statememt. An else if statement checks another condition if all prior ones are false.

Syntax

if condition {
  // Code to be executed if condition is true
} else if condition1 {
  // Code to be executed if condition1 is true
} else if condition2 {
  // Code to be executed if condition2 is true
}

Example

Example of an else if statement:

let number = 25;

if number > 40 {
  println!("The number is greater than 40.");
}
else if number > 20 {
  println!("The number is greater than 20.");
}
// In this example, the else if statement will check the condition and since number > 20 is true, it will execute the code of block inside the else if statement.

Else Statement

The else statement is used to execute a block of code when all prior conditions are false.

Syntax

if condition {
  # Code to be executed if condition is true
} else if condition1 {
  # Code to be executed if condition1 is true
} else {
  # Code to be executed if all above conditions are false
}

Example

Example of an else statement:

let number = 15;

if number > 40 {
  println!("The number is greater than 40.");
}
else if number > 20 {
  println!("The number is greater than 20.");
}
else {
  println!("The number is 20 or less.");
}
// In this example, since all the conditions are false, the code of block inside the else statement will be executed.