check if array is empty javascript

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(typeof array != 'undefined' && array.length > 0){
2	// array has elements
3}

1array.length = []