在AngularJS中格式化浮点数而不会损失精度

时间:2015-02-18 09:45:16

标签: javascript angularjs floating-point floating-accuracy repr

在AngularJS中,如何在不丢失精度的情况下在HTML页面上输出浮点数,并且不使用0进行不必要的填充?

我考虑了“数字”ng-filter(https://docs.angularjs.org/api/ng/filter/number)但是fractionSize参数会产生固定的小数:

{{ number_expression | number : fractionSize}}

我正在寻找各种其他语言被称为“精确再现性”,“规范字符串表示”,repr,往返等等,但我无法找到类似AngularJS的任何内容。

例如:

  • 1 => “1”
  • 1.2 => “1.2”
  • 1.23456789 => “1.23456789”

2 个答案:

答案 0 :(得分:2)

我自己偶然发现了一个明显的解决方案!完全删除“数字”ng-filter的使用将导致AngularJS根据我的要求将表达式简单地转换为字符串。

所以

{{ number_expression }}

而不是

{{ number_expression | number : fractionSize}}

答案 1 :(得分:0)

您可以在没有尾随零的情况下捕获零件,并在正则表达式替换中使用它。大概你想要保留一个尾随零(例如" 78.0")以保持整洁,而不是以小数分隔符结束(例如" 78。")。

var s = "12304.56780000";
// N.B. Check the decimal separator
var re = new RegExp("([0-9]+\.[0-9]+?)(0*)$");
var t = s.replace(re, '$1');  // t = "12304.5678"
t="12304.00".replace(re, "$1"); // t="12304.0"

来自regex101的解释:

/([0-9]+\.[0-9]+?)(0*)$/
    1st Capturing group ([0-9]+\.[0-9]+?)
        [0-9]+ match a single character present in the list below
            Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
            0-9 a single character in the range between 0 and 9
        \. matches the character . literally
        [0-9]+? match a single character present in the list below
            Quantifier: +? Between one and unlimited times, as few times as possible, expanding as needed [lazy]
            0-9 a single character in the range between 0 and 9
    2nd Capturing group (0*)
        0* matches the character 0 literally
            Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
    $ assert position at end of the string