如何在javascript中为返回函数的变量赋值

Question

I am trying to return a function that has an assigned variable in it. looking at the example code below:

function a(x){   
    function b(y){
        return x+y;
    }
    return b;
}

executing a(4) would return the function b in this format:

function b(y){
    return x+y;
}

now how can one make so executing a(4) returns b as below:

function b(y){
    return 4+y;
}

apologies for the title didn't know quite well how to word the question.

Answer 1

Since a(4) is what gives you b, you now need to call b(y). So if you wanted x to be 4 and y to be 5, you'd call:

a(4)(5) // returns 9

Answer 2

Assign the return value to another variable

 function a(x){ function b(y){ return x+y; } return b; } var add4 = a(4); console.log(add4(10)); var add6 = a(6); console.log(add6(15)); 

Answer 3

您的代码是正确的，使用方式是a（4）（3）。b中的x是a的参数。