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)); // true
//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.indexOf('Grapes'); // Find in String string...
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:...
Output: Add value if not exists Loop through the array to check whether a particular username value already exists and if it does do nothing, but if it doesn’t add a new object to the array. const arr = [{ id: 1, username: 'fred' }, { id: 2, username: 'bill' }, { ...
For the search feature, we check if the return type of the.indexOf(searchText)is greater than-1. If so, then the search result should betrueelsefalse. Let us look at the same example discussed above to check if an element exists in the array. ...
function checkePlugs(pluginname) { var f = "-" var plugins = navigator.plugins; if (plugins.length > 0) { for (i = 0; i < navigator.pluginslength; i++) { if (navigatorplugins[i].name.indexOf(plugin) >= 0) { f = navigator.plugins[i.descriptionsplit(pluginname)[1...
Array.prototype.hasObjectExists =function(item) {for(i = 0; i < this.length; i++) {if(this[i].id == item.id){returntrue; }//www.java2s.com}returnfalse; }; PreviousNext Related Javascript Array hashCode() Javascript Array hasItem(item) ...
// Function to check if an array contains a specific elementconstcontains=(arr,element)=>{// Iterate through the array using the Array.prototype.some methodreturnarr.some(item=>item===element);};// Sample arrayconstarr=[2,5,9,6];// Output the result of checking if the array contains...
5.`arrayToHtmlList`:数组转`li`列表 此代码段将数组的元素转换为标签,并将其附加到给定ID的列表中。 代码语言:javascript 复制 constarrayToHtmlList=(arr,listID)=>(el=>((el=document.querySelector('#'+listID)),(el.innerHTML+=arr.map(item=>`${item}`).join('')))();arrayToHtmlList(['...
The first line adds a new argument namedprop. This new argument is the name of the property we will check for the value ofstr. We usefind()instead ofindexOf()becausefind()allows us to pass a callback function. This function checks if the propertypropexists in theitemduring each iteration...