pxt-calliope/olddocs/js/return.md

Return

Exit a function.

@parent js/statement

The return statement exits a function and returns a value to the code that called the function.

Touch Develop syntax

return expression

Square function

/**
 * // return the value x * x
 * @param x TODO
 */
export function square(x: number) : number {
    let result: number
    return x * x
    return result
}

The type of expression

The type of expression should match the declared return type of the function; in the above example, the return type is Number and we see that the return expression x * x is a Number since the input parameter x is a Number.

Storing the returned value

The following code calls the square function with the number 42 and stores the output parameter in the result variable:

let result1 = square(42)

result is the default variable name for the function output, as specified in the function

Lessons

transformers

See also

function, calling functions, function parameters