function isOverflow(element) {
return element.scrollWidth > element.offsetWidth;
}
let element = document.querySelector('.ellipsis-span');
let resizeObserver = new ResizeObserver(() => {
let overflow = isOverflow(element);
if (overflow) {
console.log('内容超出，需要显示省略号');
} else {
console.log('内容未超出，不需要显示省略号');
}
});
resizeObserver.observe(element);