Can anyone explain this? please

JavaScript
1

Can anyone explain this? please

function expression(number, operation){

if(!operation)

    return number;

return operation(number);

}

javaScript learning!
2

It’s hard to say without the full code, but it looks like you are working with two arguments, a function operation and a number number. If you don’t have an operation you return the number otherwise you compute and return operation(number).

3

!operation => that mean is if i don’t have a operation ?
and why i have a tow return? there is another way to type this code?

4

Right, !operation is a test that checks if operation is falsey. In this case falsey means you don’t have an operation.

There are two return statements because there are two different results you could be returning.

1 Like
5

Thank you very much.
i will show u full code. just i wanna know how that work! and thanks wise, with all my love :blush:

function expression(number, operation){

if(!operation)

    return number;

return operation(number);

}

function five(operation) { return expression(5, operation); }

function seven(operation) { return expression(7, operation); }

function times(x) {

return function(y) {

    return y * x;

}

}

1 Like
6

gays, Hi
how can i tell JavaScript how the multiply work? like i wanna callback the multiply functions by one word, like that
five( multiply(7)).

and thanks for help!

7

In JavaScript and many other languages, it have a built in feature.

//multiplication
5 * 7
//division
5 / 7
//adition
5 + 7
//subtraction
5 - 7

So if you want to put it in a function

function multiply(a, b) {
return a * b;
}

multiply(5, 7);
1 Like
8

if you want something like five(multiply(7)) to work you need to define a five function that accepts the other function as argument.
Can be done, but it is a bit complex.