How to Check If a Value Exists in an Array in JavaScript
Topic: JavaScript / jQueryPrev|Next
Answer: Use the indexOf()
Method
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:
Example
Try this code »<script>
var fruits = ["Apple", "Banana", "Mango", "Orange", "Papaya"];
// Check if a value exists in the fruits array
if(fruits.indexOf("Mango") !== -1){
alert("Value exists!")
} else{
alert("Value does not exists!")
}
</script>
ES6 has introduced the includes()
method to perform this task very easily. But, this method returns only true
or false
instead of index number, as you can see here:
Example
Try this code »<script>
var fruits = ["Apple", "Banana", "Mango", "Orange", "Papaya"];
alert(fruits.includes("Banana")); // Outputs: true
alert(fruits.includes("Coconut")); // Outputs: false
alert(fruits.includes("Orange")); // Outputs: true
alert(fruits.includes("Cherry")); // Outputs: false
</script>
All modern browsers supports the includes()
method and it is preferred for modern applications.
Please check out the tutorial on JavaScript Arrays to learn more about the arrays.
Related FAQ
Here are some more FAQ related to this topic:
- How to remove duplicate values from a JavaScript array
- How to remove a specific item from an array in JavaScript
- How to loop through an array in JavaScript