javascript empty array

1if (array && !array.length) {
2    // array is defined but has no element
3}

1arr = [];   // set array=[]
2
3//function
4const empty = arr => arr.length = 0;
5//example
6var arr= [1,2,3,4,5];
7empty(arr) // arr=[]

1var colors = ["red","blue","green"];
2    colors = []; //empty the array

1if (array === undefined || array.length == 0) {
2    // array empty or does not exist
3}

1A = [];
2

1var arr1 = ['a','b','c','d','e','f'];
2var arr2 = arr1;  // Reference arr1 by another variable 
3arr1 = [];
4console.log(arr2); // Output ['a','b','c','d','e','f']
5