JAVASCRIPT

check if a variable is array in javascript

// inside if else check
if(Array.isArray(myVarToTest)) {
	// myVatToTest is an array
} else {
	// myVarToTest is not an array
}

check if is array js

let names=['Jhon','David','Mark'];
console.log(Array.isArray(names));
// true

let user={id:1,name:'David'};
console.log(Array.isArray(user));
// false

let age 18;
console.log(Array.isArray(age));
// false

check if element is array javascript

Array.isArray([]) //true
Array.isArray({}) //false
Array.isArray('') //false
Array.isArray(null) //false

js is array

Array.isArray([1, 2, 3]);   // true
Array.isArray({toto: 123}); // false
Array.isArray("tototruc");  // false
Array.isArray(undefined);   // false

js check if array

Array.isArray([1, 2, 3]);	// true
Array.isArray('asdf');		// false

js check if is array

if(Array.isArray(colors)){
    //colors is an array
}

js test if array

if(Array.isArray(myVarToTest)) {
	// myVatToTest is an array
} else {
	// myVarToTest is not an array
}

js check if a variable is an array

let fruit = 'apple';
let fruits = ["apple", "banana", "mango", "orange", "grapes"];

const isArray = (arr) => Array.isArray(arr);

console.log(isArray.(fruit)); //output - false
console.log(isArray.(fruits)); //output- true

javascript check if array

let variable1 = [2, 3]
let variable2 = "test";

variable1.constructor === Array; // true
variable2.constructor === Array; // false

how to check if array

// Check if something is an Array 
// just like you do with "typeof"
Array.isArray([1, 2, 3]);	// true
Array.isArray('asdf');		// false

how to check if something is array javascript

function isArray(value) {
    return Object.prototype.toString.call(value) === "[object Array]";
}

javascript Array.isArray

// all following calls return true
Array.isArray([]);
Array.isArray([1]);
Array.isArray(new Array());
Array.isArray(new Array('a', 'b', 'c', 'd'));
Array.isArray(new Array(3));
// Little known fact: Array.prototype itself is an array:
Array.isArray(Array.prototype);

// all following calls return false
Array.isArray();
Array.isArray({});
Array.isArray(null);
Array.isArray(undefined);
Array.isArray(17);
Array.isArray('Array');
Array.isArray(true);
Array.isArray(false);
Array.isArray(new Uint8Array(32));
Array.isArray({ __proto__: Array.prototype });

array check in javascript

const arr = ["name"]
console.log(Array.isArray(arr)); // true

Check if value is array

Method 1: Using the isArray method
Array.isArray(variableName)'

Method 2:
variable instanceof Array

Method 3:
variable.constructor === Array

if array javascript

// I know javascript can be hard but see this example and you will learn

// Javascript if condition and array example
var people = ["filex", "alex", "jon"];
var peopleNeeded = people[1]; // 1 is the index bc the index starts from 0
 
if (peopleNeeded <= people[1]) {
 console.log("alex needed");   
} else {
 console.log("lol");   
}

check if is array javascript

if(Object.prototype.toString.call(someVar) === '[object Array]') {
    alert('Array!');
}