javascript实现图片预加载

function load(url) {
    let imgObj = new Image(); // 创建图片对象
    imgObj.src = url;
    if (imgObj.complete) {
        console.log('is loaded')
    } else {
        imgObj.onload = () => {
           console.log('loading success')
        };
        imgObj.onerror = () => {
            console.log('loading error')
        }
    }
}