实现方法
/** * 从base64编码的图片中获取扩展名 * @param {String} base64 * @returns */ function getExtensionFromBase64(base64) { let re = new RegExp('data:image/(?<ext>.*?);base64,.*') let res = re.exec(base64) if (res) { return res.groups.ext } }
测试
let base64 = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEU' let ext = getExtensionFromBase64(base64) console.log(ext) // png
