Returns the first index at which a given element can be found in the array, or -1 if it is not present. Method of Array Implemented in JavaScript 1.6 ECMAScript Edition ECMAScript 5th Edition Syntax array.indexOf(searchElement[, fromIndex]) Parameters searchElement Element to locate in the ...
Get item index when using filter in javascript, About index: you can use indexOf(val) function to get the index of value from the array. – Krzysiek Szymczak. Nov 6, 2016 at 9:59. 1. Tags: index of an appended object in jqueryindex of element from array on click jqueryjquery get i...
我从myarray.indexOf(element) 得到 -1,即使元素似乎在 myarray 中。 下面是一些代码片段: {代码...} 警报显示 nds 确实包含 el,但警报应该只在 idx==-1 时触发,只有当 nds 不包含 el 时才会触发。 我知道我...
To access elements of an array using index in JavaScript, mention the index after the array variable in square brackets. The syntax to access an element from arrayarrat indexiis </> Copy arr[i] Read Array Element at Specific Index array[index], if used in an expression, or on the right...
The findIndex() method returns the index of the first element in an array that pass a test (provided as a function).The findIndex() method executes the function once for each element present in the array:If it finds an array element where the function returns a true value, findIndex()...
TheindexOf()method returns the first index of occurance of anarrayelement, or-1if it is not found. Example letlanguages = ["Java","JavaScript","Python","JavaScript"]; // get the index of the first occurrence of "JavaScript"letindex = languages.indexOf("JavaScript"); ...
JavaScript // Create an array. var ar = ["ab", "cd", "ef", "ab", "cd"]; // Determine the first location, in descending order, of "cd". document.write(ar.lastIndexOf("cd") + ""); // Output: 4 // Find "cd" in descending order, starting at index 2. document...
// function that returns odd numberfunctionisOdd(element){returnelement %2!==0; }// defining an array of integersletnumbers = [2,8,1,3,4]; // returns the index of the first odd number in the arrayletfirstOdd = numbers.findIndex(isOdd); ...
Array.prototype.indexOf() arrayLikeconsole.log(Array.prototype.indexOf.call(arrayLike,2));// 0console.log(Array.prototype.indexOf.call(arrayLike,5));// -1 Specification ECMAScript® 2026 Language Specification #sec-array.prototype.indexof...
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