js check if value exists in array code example
Example 1: check if array does not contain value javascript
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var n = fruits.includes("Mango"); // true
var n = fruits.includes("Django"); // false
Example 2: javascript array contains
var colors = ["red", "blue", "green"];
var hasRed = colors.includes("red"); //true
var hasYellow = colors.includes("yellow"); //false
Example 3: javascript method to see if item exists in array
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!")
}
Example 4: check value exist in array javascript
[1, 2, 3].includes(2); // true
[1, 2, 3].includes(4); // false
[1, 2, 3].includes(1, 2); // false (second parameter is the index position in this array at which to begin searching)
Example 5: javascript check if in array
var extensions = ["image/jpeg","image/png","image/gif"];
if(extensions.indexOf("myfiletype") === -1){
alert("Image must be .png, .jpg or .gif");
}