javascript - js square bracket problem

Question

import {INCREMENT} from "./types"

const mutations = {
    [INCREMENT] (state) {
      state.count++;
    }
}

[INCREMENT] Can't INCREMENT be used directly as a variable? Why do we need to add a bracket?

Answer 1

[INCREMENT]是计算INCREMENT这个变量的值作为函数名，不使用中括号是把INCREMENTThis string is used as the function name.

const INCREMENT = 'myfunc';

const mutations = {
    [INCREMENT] (state) {
      state.count++;
    }
}

Equivalent to the above code, the result is

const mutations = {
    myfunc(state) {
      state.count++;
    }
}

And

const INCREMENT = 'myfunc';
const mutations = {
    INCREMENT (state) {
      state.count++;
    }
}

The result of

is

const mutations = {
    INCREMENT(state) {
      state.count++;
    }
}

Answer 2

These are computed property names

https://developer.mozilla.org...