If the value exists, then the function will return the index value of the element, else it will return -1Syntax put-array-or-string-here.indexOf() Code //code to check if a value exists in an array using javascript indexOf var fruits_arr = ['Apple', 'Mango', 'Grapes', 'Orange'...
const found = arr.some(el => el.username === name); if (!found) arr.push({ id, username: name }); return arr; } console.log(add(arr, 'ted')); Source: stackoverflow.com Check if one element exists in an array of objects var memberships = [{ id: 1, type: 'guest' ...
constarray=[1,2,3,4,5];constvalue=3;if(array.indexOf(value)!==-1){console.log("数组中存在该值");}else{console.log("数组中不存在该值");} 使用some()方法: some()方法用于检查数组中是否有元素满足某个条件,如果有则返回true,否则返回false。
let array = [1, 2, 3, 4, 5]; let valueToFind = 3; if (array.find(element => element === valueToFind) !== undefined) { console.log('Value exists in the array'); } else { console.log('Value does not exist in the array'); } ...
Find Element in Array Write a JavaScript function to find an array containing a specific element. Test data: arr = [2, 5, 9, 6]; console.log(contains(arr, 5)); [True] Visual Presentation: Sample Solution: JavaScript Code: // Function to check if an array contains a specific elementfu...
In v3.0.0 or newer, .only() can be used multiple times to define a subset of tests to run: describe('Array', function() { describe('#indexOf()', function() { it.only('should return -1 unless present', function() { // this test will be run }); it.only('should return the...
$.inArray(element, array, [fromIndex]) ⇒ number Get the position of element inside an array, or -1 if not found.$.isArray $.isArray(object) ⇒ boolean True if the object is an array.$.isFunction $.isFunction(object) ⇒ boolean True if the object is a function.$...
{ // Get the element from the weak reference, if it still exists const element = this.ref.deref(); if (element) { element.textContent = ++this.count; } else { // The element doesn't exist anymore console.log("The element is gone."); this.stop(); this.ref = null; } }; tick...
var elemOne = document.forms[0].elements[0]; // first element in first form As with images, elements could be accessed by array entry, with position in the array determined by the position of the element in the web page. In addition, elements given an identifier could also be accessed ...
What I will need to do before asigning the first element in the array: Pic[0] = "images/Pic1.bmp"Is to first check if "images/Pic1.bmp" exists ?x_xhtml 複製 var Pic = new Array() Pic[0] = "images/Pic1.bmp"; Pic[1] = "images/Pic2.bmp"; Pic[2] = "images/Pic3.bmp...