使用JavaScript中的参数保存对函数的引用

Question

I am calling a function at several places within my app. This function takes several parameters whose values might change. To avoid re-typing, I want to save a reference to this function so that I can simply call this referred function everywhere. Here is the simplified code:

const func1 = (a,b,c) => a + b + c; 
let a = 1, b = 2, c = 3;
const func2 = func1.bind(this, a, b, c);
func2();
//prints 6
c = 6;
func2();
//still prints 6!

How can I ge func1 to be executed with updated values of a , b and c by calling func2 ?

Answer 1

Use arrow function:

 const func1 = (a,b,c) => a + b + c; let a = 1, b = 2, c = 3; const func2 = () => func1(a, b, c); console.log(func2()); c = 6; console.log(func2()); 

Answer 2

You can bind the function to an array of [a, b, c] instead, and then change the property at index 2:

const func1 = (a,b,c) => a + b + c; 
const params = [1, 2, 3];
const func2 = () => func1(...params);
func2();
params[2] = 6;
func2();

If you only change c , you could consider binding the function to a and b , and then passing the changing c :

const func1 = (a,b,c) => a + b + c; 
const params = [1, 2];
const func2 = (c) => func1(...params, c);
func2(3);
func2(6);

Answer 3

If you want to use params from scope where you declare your function, just skip those params in function signature

 const f = () => a + b + c; let a = 1, b = 2, c = 3; console.log(f()); c = 6; console.log(f()); 

Answer 4

Instead of this const func2 = func1.bind(this, a, b, c);

You can use this function(arrow): const func2 = () => func1(a, b, c);