1if (typeof array !== 'undefined' && array.length === 0) {
2    // the array is defined and has no elements
3}
4

1if (array === undefined || array.length == 0) {
2    // array empty or does not exist
3}
4

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

1if (Array.isArray(array) && array.length) {
2    // array exists and is not empty
3}

1if(array.length > 0)

1var colors=undefined;
2if(!colors?.length){
3	console.log("empty")
4}else{
5	// I am not empty
6}