javascript 在javascript中将数字四舍五入为一位小数
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Rounding a number to one decimal in javascript
提问by Robert Martens
Possible Duplicate:
How do you round to 1 decimal place in Javascript?
The following code, displays the total distance covered, on a particular route, displayed on google maps. I managed to convert the number from kilometers to miles. Here is the code for the function:
以下代码显示在特定路线上覆盖的总距离，显示在谷歌地图上。我设法将数字从公里转换为英里。下面是该函数的代码：
function computeTotalDistance(result) {
var total = 0;
var myroute = result.routes[0];
for (i = 0; i < myroute.legs.length; i++) {
total += myroute.legs[i].distance.value;
}
total = total *0.621371/ 1000.
document.getElementById('total').innerHTML = total + ' mi';
The total is displayed as 41.76483039399999 mi. How would round off the totalto one decimal place?
总数显示为41.76483039399999 mi。如何将四舍五入total到小数点后一位？
回答by Joseph Silber
Use toFixed:
使用toFixed：
var total = 41.76483039399999;
total = total.toFixed(1) // 41.8
Here's the fiddle: http://jsfiddle.net/VsLp6/
这是小提琴：http: //jsfiddle.net/VsLp6/
回答by PinkElephantsOnParade
Math.round(total * 10) / 10
This results in a number. toFixed() gives a string, as detailed in other answers.
这导致了一个数字。toFixed() 给出一个字符串，如其他答案中所述。
回答by Paul S.
You are looking for Number.prototype.toFixed; 41.76483039399999.toFixed(1) === "41.8";
您正在寻找Number.prototype.toFixed；41.76483039399999.toFixed(1) === "41.8";
function computeTotalDistance(result) {
var total = 0, myroute = result.routes[0];
for (i = 0; i < myroute.legs.length; i++) {
total += myroute.legs[i].distance.value;
}
total = (total * 0.621371 / 1000).toFixed(1);
document.getElementById('total').innerHTML = total + ' mi';
}
There are a very many other ways to achieve this, for example, without using any methods from Mathor instances of Number
有很多其他方法可以实现这一点，例如，不使用任何方法Math或实例Number
(~~(10 * total) + (~~(100 * total) % 10 >= 5))/10 + '' // "41.8"
// ( 417 + (6 >= 5) )/10 = 41.8
回答by igarcia
There is a function to do what you want:
有一个功能可以做你想做的事：
var total = 41.76483039399999; print(x.toFixed(2));
无功总计 = 41.76483039399999；打印（x.toFixed（2））；
It will be printed 41.76
它将打印 41.76
