javascript cehck if array is empty

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

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

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

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

if(array.length > 0)

array.length

if (typeof image_array !== 'undefined' && image_array.length > 0) {
    // the array is defined and has at least one element
}

Array.isArray(emptyArray) && emptyArray.length

array.length = []

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