如何在另一个函数内调用一个函数

Question

I'm trying to call a function inside another function in javascript, actually trying to call populateCurrencies() inside startApp() . What am I doing wrong?

const startApp = () => {
   const populateCurrencies = (); 

function populateCurrencies() {

    alert(return this.option.value + " " + this.option.textContent);
}

const startApp = () {};

Answer 1

You are using a invalid syntax.

You declare functions like this (with arrow function expression).

const myFunc = () => {
 // Code to run here...
}

And you call your function like this.

myFunc();

Not const myFunc = () {}; like it is in your example.

Also, const is a constant, you can't have multiple constants with the same name, so that's an error as well. And if you want to reassign values to a variable you have to use let instead. But that's beside the point since you won't need those extra variable declarations that you have now when you call the functions.