I have two questions about array of object in javascript

Question

the code is simply, I need to create some fruits and their price and quantities in an array of object like this :

cartTotal ( [
  { name: 'Apple', price: 4, quantity: 2 }, 
  { name: 'Orange', price: 3, quantity: 3 }
]);

    function cartTotal(cartArray) {
        let total = 0;
        
    cartArray.forEach(function(cartItem) {
        total = total + cartItem.price * cartItem.quantity;
          });
        console.log(total);
      }

my first question is why I cannot add '=' on a first line like this:

cartTotal = ( [

but in the other html I can use '=' like:

let todos = [
              {title: 'Get groceries', dueDate: '2021-10-04' },
              {title: 'Wash car', dueDate: '2021-02-03' },
              {title: 'Make dinner', dueDate: '2021-09-04'}
           ]

my second question is, on the 6 lines :

function cartTotal(cartArray) {

why the function name "cartTotal" must equal to array name "cartToal", if I change function's name, it can not work.

You need to look at simple javascript code samples first. There are plenty of resources online. ex: developer.mozilla.org/en-US/docs/Learn/… — Tushar Shahi
– Tushar Shahi, Commented Jun 22, 2022 at 18:05
The first statement is not a definition of a variable, it's a function call with an array as parameter. The function cartTotal is defined later. — IT goldman
– IT goldman, Commented Jun 22, 2022 at 18:06

Ram · Accepted Answer · 2022-06-22 18:26:19Z

1

my first question is why I cannot add '=' on a first line like this

You can do that. It effectively sets the value of cartTotal from being a function to an array. JavaScript functions are hoisted.

JavaScript Hoisting refers to the process whereby the interpreter appears to move the declaration of functions, variables or classes to the top of their scope, prior to execution of the code.

This is why you can call the function before declaring it.

() can be used as invocation operator or a grouping operator. functionName() calls a function identified as functionName. variable = ([]) sets the value of the variable variable to an array. The value doesn't have to be an array, of course.

edited Jun 22, 2022 at 18:26

answered Jun 22, 2022 at 18:21

Ram

145k16 gold badges174 silver badges201 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

I have two questions about array of object in javascript

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related