JS中保留小数位数

时间:2023-03-09 14:33:48
JS中保留小数位数

、1.2.toFixed(2)

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浮点数进行四舍五入设置指定小数位的数值

、2.toFixed(2)

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整数尝试,但是在JS中会被认为是对象名,以至于无法使用

三、"1.2".toFixed(2)

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由于toFixed方法是针对Number类型的,所以string类型的即使能够转换成数字,也不能使用这个方法

四、var a=1;a.toFixed(2);

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构造整数对象,那么就可以调用了

http://www.w3school.com.cn/jsref/jsref_tofixed.asp

下面是w3school中的介绍:

toFixed()这个方法是针对Number 对象(Number 对象是原始数值的包装对象)。

toFixed() 方法可把 Number 四舍五入为指定小数位数的数字。

NumberObject.toFixed(num)
参数 描述
num 必需。规定小数的位数,是 0 ~ 20 之间的值,包括 0 和 20,有些实现可以支持更大的数值范围。如果省略了该参数,将用 0 代替。

返回值

返回 NumberObject 的字符串表示,不采用指数计数法,小数点后有固定的 num 位数字。如果必要,该数字会被舍入,也可以用 0 补足,以便它达到指定的长度。如果 num 大于 le+21,则该方法只调用 NumberObject.toString(),返回采用指数计数法表示的字符串。

抛出

当 num 太小或太大时抛出异常 RangeError。0 ~ 20 之间的值不会引发该异常。有些实现支持更大范围或更小范围内的值。

当调用该方法的对象不是 Number 时抛出 TypeError 异常。

因为需要使用number类型,所以可以将对象转换为number类型。

parseFloat(obj),parseInt(obj)转换都是可以的

JS中保留小数位数

还有别的形式,不过实际上主要是string的类型转换