通过 Javascript 中的匹配替换

Question

我需要匹配数字后跟一个单位，并使用 Java 脚本将它们替换为数字+下划线+单位。

我编写了这段代码，它没有产生我想要达到的结果。

var x = myFunction("I have 3 billion dollars");

function myFunction(text) {
return  text.replace(/(\d+\.?(?:\d{1,2})?) (\bmillion\b|\bbillion\b|\bbillion\b|\bmillions\b|\bbillions\b|\btrillion\b|\btrillions\b|\bmeter\b|\bmeters\b|\bmile\b|\bmiles\b|\%)/gi, function (match) {
          return "<span class='highlighted'>" + match[1] + "_" + match[2] + "</span>";
    });
 }

上面的代码应该return "I have 3_billion dollars"（但就替换而言它是returns _b）。由于我是 Java 的新手，如有任何建议，我们将不胜感激。

编辑已经有很多有用的提示！这里有更多输入示例：

the street is 4.5 miles long
the budget was 430.000 dollars

Answer 1

match 不是数组，而是字符串。你可以 split 通过 ' ' 加入 _

var x = myFunction("I have 3 billion dollars");

function myFunction(text) {
return  text.replace(/(\d+\.?(?:\d{1,2})?) (\bmillion\b|\bbillion\b|\bbillion\b|\bmillions\b|\bbillions\b|\btrillion\b|\btrillions\b|\bmeter\b|\bmeters\b|\bmile\b|\bmiles\b|\%)/gi, function (match) {
          console.log(match)
          return "<span class='highlighted'>" +match.split(' ').join('_')+ "</span>";
    });
 }
console.log(x)

Answer 2

我们可以将 str.replace 与您的原始表达式一起使用，如果可行的话：

const regex = /(\d+\.?(?:\d{1,2})?) (\bmillion\b|\bbillion\b|\bbillion\b|\bmillions\b|\bbillions\b|\btrillion\b|\btrillions\b|\bmeter\b|\bmeters\b|\bmile\b|\bmiles\b|\%)/gm;
const str = `3 billion
3 million`;
const subst = `<span class='highlighted'>" _ "</span>`;

// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);

console.log('Substitution result: ', result);

此外，我们可以稍微简化一下表达式：

(\d+\.?(?:\d{1,2})?) (\bmillions?\b|\bbillions?\b|\btrillions?\b|\bmeters?\b|\bmiles?\b|\%)

const regex = /(\d+\.?(?:\d{1,2})?) (\bmillions?\b|\bbillions?\b|\btrillions?\b|\bmeters?\b|\bmiles?\b|\%)/gm;
const str = `3 billion
3 million
3 %
2 meters`;
const subst = `<span class='highlighted'>" _ "</span>`;

// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);

console.log(result);

Demo

正则表达式

如果不需要此表达式并且您希望对其进行修改，请访问此 link regex101.com。

正则表达式电路

jex.im 可视化正则表达式：

Answer 3

给你一个更简单更清晰的例子

let regex = /\d+ (million|billion|millions|billions|trillion|trillions|meter|meters|mile|miles)/g

let match = "I have 3 billion dollars".match(regex)
let replace = match.map(x => x.split(" ").join("_"))

console.log(replace)

通过 Javascript 中的匹配替换

Replacement by matching in Javascript

javascript

regex

replace

regex-group

regex-lookarounds

Demo

正则表达式

正则表达式电路