check if is array javascript code example

Example 1: javascript check if array is empty

if (typeof array !== 'undefined' && array.length === 0) {
    // the array is defined and has no elements
}

Example 2: if object is array javascript

Array.isArray(object);

Example 3: 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
}

Example 4: validate array javascript

Array.isArray([1, 2, 3]);  // true
Array.isArray({foo: 123}); // false
Array.isArray('foobar');   // false
Array.isArray(undefined);  // false

Example 5: javascript check if is array

var colors=["red","green","blue"];

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

Example 6: javascript test if it is an array

// If you want to test if a variable (object) is an instance of 
// an array. You can use the Array.isArray(varName) method
// this method takes one argument, the variable or object you want to test
// and returns true, if the argument is an array 
// or false, if the argument is not an array

if (Array.isArray(object)) {
	// is true
} else {
	// is false
}

Array.isArray([1, 2, 3, 4]); // Returns true
Array.isArray(4); // returns false
// this could be used for flattening an array of arrays