50 lines
1.1 KiB
Markdown
50 lines
1.1 KiB
Markdown
# Return
|
|
|
|
Exit a function.
|
|
|
|
### @parent js/statement
|
|
|
|
|
|
The return statement exits a [function](/js/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](/lessons/transformers)
|
|
|
|
### See also
|
|
|
|
[function](/js/function), [calling functions](/js/call), [function parameters](/js/functionparameters)
|
|
|