js根据图片路径获取图片文件大小

<input type="text" value="域名+{$imagesrc}" id="imagesrc">

<script>
let imagesrc = document.getElementById("imagesrc");
const xhr = new XMLHttpRequest();
xhr.open('HEAD', imgPath, true);
xhr.onload = function() {
    if (this.status === 200) {
        const contentLength = parseInt(this.getResponseHeader('Content-Length'));

        // 默认小数点后十位
        const kbSize = contentLength / 1024;
        console.log(`图片大小为：${kbSize} KB。`);
    } else {
        console.log('图片请求失败。');
    }
};
xhr.send();
</script>

保留小数点后一位，默认四舍五入

let size = 45.8251953125;
let roundedSize = size.toFixed(1);
console.log(roundedSize);

保留小数点后一位，取消四舍五入

let size = 45.8251953125;
let roundedSize = Math.floor(size * 10) / 10;
console.log(roundedSize);

保留小数点后二位，取消四舍五入

let size = 45.8251953125;
let roundedSize = Math.floor(size * 100) / 100;
console.log(roundedSize);

保留0位，并取消四舍五入

let size = 45.8251953125;
let roundedSize = Math.floor(size);
console.log(roundedSize);