jQuery.inArray( value, array ) 搜索数组中指定值并返回它的索引(如果没有找到则返回-1)。 value要搜索的值。 array一个数组,通过它来搜索。 当然,处于学习,自己也去写了这样的函数: 代码如下: function inArray1(needle,array,bool){ if(typeof needle=="string"||typeof needle=="number"){ for(var ...
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', 'Fig', 'Cherry']; var string = "Orange"; // Find in Array fruits_arr.indexOf('Tomato'); fruits_arr.index...
To check if a variable is an array in Javascript is essential to handle data appropriately. We will discuss three different approaches to check if a variable is an array or not. We are having an array and a string, and our task is to check if a variable is an array in JavaScript. ...
arr.find(function(value) { if(value === 要查找的值) { ... } }) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 方法三:array.findIndex() array.findIndex()和array.find()十分类似,返回第一个符合条件的数组元素的位置,如果所有元素都不符合条件,则返回-1。 findIndex() 方法为数组中的每个...
Check if the value exists in Array in Javascript Example: const fruits = ["Banana", "Orange", "Apple", "Mango"]; fruits.includes("Mango"); check if an item exists in an array: const nums = [ 1, 3, 5, 7]; console.log(nums.includes(3));...
Below is an example to find if the string is a palindrome using JavaScript String and Array Methods ? Open Compiler // Function to check for Palindrome function isPalindrome(str) { const lowerCaseStr = str.toLowerCase(); const modifiedStr = lowerCaseStr.replace(/[\W_]/g, ''); const re...
Alternatively, it can also be used as typeof() method in JavaScript.Syntax:typeof(variable); Example 1:str = "This is my place."; if (typeof str == String) { console.log('The variable is a String.'); } else { console.log('The variable is not a String.'); } ...
function isObject(val) {returnval&& typeofval==='object'&& !Array.isArray(val);} 8. Empty 当if (obj) 无法满足需求时。 functionisEmpty(obj) {returnObject.keys(obj).length===0;} 9. UUID 生成器 即时唯一 ID——无需...
You can use the indexOf() method to check whether a given value or element exists in an array or not. The indexOf() method returns the index of the element inside the array if it is found, and returns -1 if it not found. Let's take a look at the following example:...
conststring='not array';string.length;// 9 Even an object can havelengthproperty if we set it 😱 constobject={length:2};constarray=['🍝','🍜','🍲'];typeofarray==='object'&&Boolean(array.length);// truetypeofobject==='object'&&Boolean(object.length);// true <-- 😱 ...