Javascript - 如何正确使用 replace() 函数

Question

我愿意做以下事情:

我有:

    var distance1 = "5.5 Km";
    var distance2 = "5,5 Km";
    //The below works as expected and returns 5.5
    var finalDistance = distance1.replace( /[^\d\.]*/g, '');

    //However the below doesn't and print 55 instead
    distance2.replace( /[^\d\.]*/g, '');

    //I've tried the below too and it throws 5,5. But I want 5.5
    distance2.replace( /[^\d\.\,]*/g, '');

Answer 1

首先，将所有出现的,替换为.，然后将非数字字符(.除外)替换为'' :

distance2 = distance2.replace( /,/g, '.').replace(/[^\d\.]+/g, '');

哪里:

/,/g : matches all commas ',' that will be replaced by '.'
/[^\d\.]+ : matches any sequence of non-digit and non-dot ('.') characters that will be removed (replaced by the empty string '').

第一个将 "5,55 KM" 替换为 "5.55 KM"，然后第二个将后者转换为 "5.55"。

注意:如果您只有一个逗号，或者只对第一个遇到的逗号感兴趣，那么您可以使用:replace(',', '.')而不是 replace(/,/g, '.')。

如果您只使用浮点表示，您可以使用 parseFloat 而不是第二个 replace:

var number = parseFloat(distance2.replace(/,/g, '.'));