JSFiddle - React, Tailwind, and code Playground

by Rebecca Chen

JavaScript

// call by reference or call by value

var numArray = [1,3,5];
function doubleSecond (array) {
	array[1] *= 2;
}

doubleSecond (numArray);
alert (numArray);  // get [1,6,3]

// ... array as argument: call by "reference"

var array = ['a', 3, 5]; // is ok, but using Object is better
var personTom = {
	name: 'Tom', // not ';'
  salary: 30000,
  sex: 'M'
};

var checkPerson = function(p) {
	console.log (p.name + "'s salary is " + p.salary);
  p.checked = true;  //adding a new attribute to object IS ok
}

checkPerson (personTom);
console.log (personTom);