JAVASCRIPT

get if there is a value in an array node js

myArray = Array(/*element1, element2, etc...*/);

// If the array 'myArray' contains the element 'valueWeSearch'
if(myArray.includes(valueWeSearch))
{
 	// Do something
}

how to check if an element is in an array javascript

const fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.includes("Mango");

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

Check if the value exists in Array in Javascript

var army= ["Marcos", "DeltaForce", "Seals", "SWAT", "HeadHunters"];  
  
if(army.indexOf("Marcos") !== -1)  {  
  console.log("Yes, the value exists!")  
}else{  
  console.log("No, the value is absent.")  
}  

how to check if an element is in array javascript

array.includes('element that need to be checked') //returns true or false 

js access array value if exist

myArr?.[index]

javascript - Determine whether an array contains a value

var contains = function(needle) {
    // Per spec, the way to identify NaN is that it is not equal to itself
    var findNaN = needle !== needle;
    var indexOf;

    if(!findNaN && typeof Array.prototype.indexOf === 'function') {
        indexOf = Array.prototype.indexOf;
    } else {
        indexOf = function(needle) {
            var i = -1, index = -1;

            for(i = 0; i < this.length; i++) {
                var item = this[i];

                if((findNaN && item !== item) || item === needle) {
                    index = i;
                    break;
                }
            }

            return index;
        };
    }

    return indexOf.call(this, needle) > -1;
};