how to know array is empty 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: javascript empty array

arr = [];   // set array=[]

//function
const empty = arr => arr.length = 0;
//example
var arr= [1,2,3,4,5];
empty(arr) // arr=[]