//超过两位小数 小数会进1 //如果是两位小数 则值不变function upFixed (num, fix) {// num为原数字，fix是保留的小数位数let result = '0'if (Number(num) && fix > 0) {// 简单的做个判断fix = +fix || 2num = num + ''if (/e/.test(num)) {// 如果是包含e字符的数字直接返回result = num} else if (!/\./.test(num)) {// 如果没有小数点result = num + `.${Array(fix + 1).join('0')}`} else {// 如果有小数点num = num + `${Array(fix + 1).join('0')}`let reg = new RegExp(`-?\\d*\\.\\d{0,${fix}}`)let floorStr = reg.exec(num)[0]if (+floorStr >= +num) {result = floorStr} else {let floorNumber = +floorStr + +`0.${Array(fix).join('0')}1`let point = /\./.test(floorNumber + '') ? '' : '.'let floorStr2 = floorNumber + point + `${Array(fix + 1).join('0')}`result = reg.exec(floorStr2)[0]}}}return result}let number = upFixed(0.651,2)console.log(number)
