js保留四位小数

超过4位截取保留4位，不足4位保留原位数不补0

//保留4位小数
    var number = 12.3321432;
    number = String(number).replace(/^(.*\..{4}).*$/,"$1");
    number = Number(number); // number = 12.3321

    //保留2位小数
    var reg = /^(.*\..{2}).*$/;
    var number2 = 12.3;
    number2 = String(number2).replace(reg ,"$1");
    number2 = Number(number2); // number2 = 12.3  不足保留位数不补0

超过4位截取保留4位，不足4位补足0

getFloat = function(number, n) {
	n = n ? parseInt(n) : 0;
	if(n <= 0) {
		return Math.round(number);
	}
	number = Math.round(number * Math.pow(10, n)) / Math.pow(10, n); //四舍五入
	number = Number(number).toFixed(n); //补足位数
	return number;
};
console.log(getFloat('0', 4)); //0.0000
console.log(getFloat('2.08', 4)); //2.0800
console.log(getFloat('2.08500', 4)); //2.0850
console.log(getFloat('2.08996', 4)); //2.0900
console.log(getFloat('2.08994', 4)); //2.0899

toFixed()方法

var a =123.456789;

alert(a.toFixed(4));// 四舍五入保留四位小数

需注意，保留两位小数，将数值类型的数据改变成了字符串类型

Math.floor()向下取整

let numBoolean = Math.floor((this.editFormData.amount / this.thresholdYuan) * 10000) / 10000 >= 0.005

标签：getFloat,console,log,number,js,number2,四位,Math,小数
来源： https://blog.csdn.net/weixin_49075393/article/details/121750723