Theincludes()method is case sensitive. Syntax array.includes(element,start) Parameters ParameterDescription elementRequired. The value to search for. startOptional. Start position. Default is 0. Return Value TypeDescription A booleantrueif the value is found, otherwisefalse. ...
// lastIndexOf() method function isGreaterThan5(element, index, array) { return element > 5; } function func() { // Original array var array = [2, 5, 8, 1, 4]; // Checking for condition in array var value = array.some(isGreaterThan5); document.write(value); } func(); 1...
// JavaScript to illustrate// lastIndexOf() methodfunction isGreaterThan5(element, index, array) {return element > 5;} function func() { // Original arrayvar array = [2, 5, 8, 1, 4]; // Checking for condition in a...
Return a new array: Other array methods, such as Concat, Slice, and Map, return a new array without modifying the original array. Accept arguments: Many array methods accept arguments that allow you to customize their behaviour. For example, the.slice() method accepts start and end indices a...
In the above example, we have passed two argument values in theinclude()method. languages.includes("Java", 2)returnsfalsesince the method doesn't find'Java'fromsecondindex of the array. Inlanguages.includes("Java", -3), the method starts searching'Java'from thethird lastelement because of ...
if(value instanceOf Array){} if(Array.isArray(value)){} 2.转换方法 toLocalString() 把数组转换为本地数组,并返回结果。 toString() 把数组转换为字符串,并返回结果。 valueOf() 返回数组对象的原始值。 join() 把数组的所有元素放入一个字符串。元素通过指定的分隔符进行分隔。
For strings, theincludes()method has the following syntax: string.includes(substring,startPosition); For arrays, theincludes()method has the following syntax: array.includes(element,fromIndex); Parameters substring(for strings) /element(for arrays): The value that you want to search for within the...
The map() method creates a new array with the results of calling a function for every array element.The map() method calls the provided function once for each element in an array, in order.Note: map() does not execute the function for array elements without values....
The slice() Method The splice() Method The copyWithin() Method Syntax array1.concat(array2,array3, ...,arrayX) Parameters ParameterDescription array1,...Required. The array(s) to be concatenated. Return Value TypeDescription ArrayThe content from the joined arrays. ...
The some() method checks if any of the elements in an array pass a test (provided as a function).The some() 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, some() returns true (and does ...