How can I use the object's functions in pure JavaScript, without using jquery?

Question

I am trying to use functions from an object, but having no success.

let ops = [
    {'*': (a, b) => a * b}, 
    {'/': (a, b) => a / b},
    {'+': (a, b) => a + b},
    {'-': (a, b) => a - b}
];

let res = [];
let current;

for (var i = 0; i < ops.length; i++) {
   current = ops[i];
   res = current(4, 2);
   console.log(res);
}

You'd probably have an easier time if you had one object or one array, as opposed to an array of objects. — Tyler Roper, Feb 26 '20 at 21:01
Use eval https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval — nll_ptr, Feb 26 '20 at 21:02
@nullptr.t That solves a different problem, which may not be desirable. — Dave Newton, Feb 26 '20 at 21:03
@nullptr.t no [avoid eval](https://stackoverflow.com/questions/86513/why-is-using-the-javascript-eval-function-a-bad-idea). — Chris W., Feb 26 '20 at 21:03
`current` is an object containing one property. it's not a function itself. — Dan O, Feb 26 '20 at 21:03

score 5 · Accepted Answer · answered Feb 26 '20 at 21:02

Without changing ops, you need to take the function out of the object by getting all values of the object and take the first one.

 let ops = [
    {'*': (a, b) => a * b}, 
    {'/': (a, b) => a / b},
    {'+': (a, b) => a + b},
    {'-': (a, b) => a - b}
];

let res = [];
let current;

for (var i = 0; i < ops.length; i++) {
   current = Object.values(ops[i])[0];
   res = current(4, 2);
   console.log(res);
}

A smarter approach is to use only the functions in an array.

 let ops = [
        (a, b) => a * b, 
        (a, b) => a / b,
        (a, b) => a + b,
        (a, b) => a - b
    ];

let res = [];
let current;

for (var i = 0; i < ops.length; i++) {
   current = ops[i];
   res = current(4, 2);
   console.log(res);
}

How can I use the object's functions in pure JavaScript, without using jquery?

1 Answers1