If statement

In Rell, the if statement is used to create conditional logic that allows you to execute different blocks of code based on whether a specified condition is true or false.

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

condition: This is the expression that evaluates to either true or false. If the condition is true, the code within the first block (between {}) will be executed. If the condition is false, the code within the else block (also between {}) will be executed.

Example:

if (x == 5) print('Hello');

if (y == 10) {
    print('Hello');
} else {
    print('Bye');
}

if (x == 0) {
    return 'Zero';
} else if (x == 1) {
    return 'One';
} else {
    return 'Many';
}

In this example,

if (x == 5) print('Hello');

This snippet checks if the value of variable x is equal to 5. If the condition is true, it prints "Hello".

if (y == 10) {
    print('Hello');
} else {
    print('Bye');
}

In this snippet, if the value of variable y is equal to 10, it prints "Hello". If the condition is false, it prints "Bye". This is a correct representation of an if statement with an else block.

if (x == 0) {
    return 'Zero';
} else if (x == 1) {
    return 'One';
} else {
    return 'Many';
}

This snippet involves an if-else if-else chain. If x is 0, it returns the string "Zero". If x is 1, it returns the string "One". If neither of these conditions is met, it returns the string "Many".

You can also use the if statement as an expression:

function my_abs(x: integer): integer = if (x >= 0) x else -x;