how to create array javascript code example
Example 1: list javascript
//Creating a list
var fruits = ["Apple", "Banana", "Cherry"];
//Creating an empty list
var books = [];
//Getting element of list
//Lists are ordered using indexes
//The first element in an list has an index of 0,
//the second an index of 1,
//the third an index of 2,
//and so on.
console.log(fruits[0]) //This prints the first element
//in the list fruits, which in this case is "Apple"
//Adding to lists
fruits.push("Orange") //This will add orange to the end of the list "fruits"
fruits[1]="Blueberry" //The second element will be changed to Blueberry
//Removing from lists
fruits.splice(0, 1) //This will remove the first element,
//in this case Apple, from the list
fruits.splice(0, 2) //Will remove first and second element
//Splice goes from index of first argument to index of second argument (excluding second argument)
Example 2: javascript array
//create an array like so:
var colors = ["red","blue","green"];
//you can loop through an array like this:
for (var i = 0; i < colors.length; i++) {
console.log(colors[i]);
}
Example 3: how to create an array in node js
// Don't need to provide elements directly, but you can
// FIRST OPTION
var myArray = new Array(/*elements1, elements2*/);
// SECOND OPTION
var mySecondArray = [/*element1, element2*/];
Example 4: what are the two ways to create an array in javascript examples?
let scores = Array(10);
Example 5: js arrays
// Making an array:
const colors = ["red", "orange", "yellow"];
// Arrays are indexed like strings:
colors[0]; // "red"
// They have a length:
colors.length; //3
// Important array methods:
//push(value) - adds value to the END of an array
//pop() - removes and returns last value in array
//unshift(val) - adds value to START of an array
//shift() - removes and returns first element in an array
Example 6: new array from javascript
// Sequence generator function (commonly referred to as "range", e.g. Clojure, PHP etc)
const range = (start, stop, step) => Array.from({ length: (stop - start) / step + 1}, (_, i) => start + (i * step));
// Generate numbers range 0..4
range(0, 4, 1);
// [0, 1, 2, 3, 4]
// Generate numbers range 1..10 with step of 2
range(1, 10, 2);
// [1, 3, 5, 7, 9]
// Generate the alphabet using Array.from making use of it being ordered as a sequence
range('A'.charCodeAt(0), 'Z'.charCodeAt(0), 1).map(x => String.fromCharCode(x));
// ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"]