一组arguments可以同时调用两个函数吗？

Question

Out of curiosity, is it possible to call two functions at once?

For example, here is some pseudo code:

// custom logging function:
function custom_log(string) {
  console.log(string);
}

(console.log && custom_log)("Hello World.");

If it's possible how?

Answer 1

No, you can't say "here are two functions, here's one set of arguments, call them both with the same arguments". But you can pre-define the arguments in a variable and pass that to both functions, which is probably the most concise if you use object destructuring for your parameters:

function custom_log({output, errorVal}) {
  console.log(output);
  console.error(errorVal);
}
const args = {
    output: 'Hello, world',
    errorVal: 'Some error happened'
};
console.log(args);
custom_log(args);

You could also just create a helper function that iterates through an array of passed functions and calls them all:

function callAllWith(functionList, ...args) {
   functionList.forEach(fn => fn(...args));
}
callAllWith([console.log, custom_log], 'Hello, world!');

Answer 2

Not "simultaneous" in any parallel-processing sense, no.

But yes, you could easily write a higher-order function that takes multiple functions and creates a new one that you need to call only once:

function atOnce(...fns) {
    return function(...args) {
         for (const fn of fns)
             fn.apply(this, args);
    };
}

atOnce(console.log, custom_log)("Hello World");

Answer 3

*** Just combine code of both and use one function use new lightOn() I merged code for toggle in it. All functions run sequentially so its better to run them in same block.