How to check if array element exists or not in javascript?

Question

I am working with Titanium, my code looks like this:

var currentData = new Array();

if(currentData[index]!==\"\"||currentData[index]!==null||currentData[ind         


        

Answer 1

var fruits = ["Banana", "Orange", "Apple", "Mango"];
if(fruits.indexOf("Banana") == -1){
    console.log('item not exist')
} else {
	console.log('item exist')
}

Answer 2

(typeof files[1] === undefined)?
            this.props.upload({file: files}):
            this.props.postMultipleUpload({file: files widgetIndex: 0, id})

Check if the second item in the array is undefined using the typeof and checking for undefined

Answer 3

Use typeof arrayName[index] === 'undefined'

i.e.

if(typeof arrayName[index] === 'undefined') {
    // does not exist
}
else {
    // does exist
}

Answer 4

you can simply use this:

var tmp = ['a', 'b'];
index = 3 ;
if( tmp[index]){
    console.log(tmp[index] + '\n');
}else{
    console.log(' does not exist');
}

Answer 5

If elements of array are also simple objects or arrays, you can use some function:

// search object
var element = { item:'book', title:'javasrcipt'};

[{ item:'handbook', title:'c++'}, { item:'book', title:'javasrcipt'}].some(function(el){
    if( el.item === element.item && el.title === element.title ){
        return true; 
     } 
});

[['handbook', 'c++'], ['book', 'javasrcipt']].some(function(el){
    if(el[0] == element.item && el[1] == element.title){
        return true;
    }
});

Answer 6

Simple way to check item exist or not

Array.prototype.contains = function(obj) {
    var i = this.length;
    while (i--)
       if (this[i] == obj)
       return true;
    return false;
}

var myArray= ["Banana", "Orange", "Apple", "Mango"];

myArray.contains("Apple")