在 Javascript 中通过匹配替换

Question

我需要匹配数字后跟一个单位，并使用 Javascript 用数字+下划线+单位替换它们。我想出了这个代码，它不会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>";    }); }上面的代码应该返回“我有 3_billion 美元”（但就替换而言，它返回 _b）。由于我是 Java 新手，任何建议将不胜感激。编辑 已经有很多有用的提示了！这里还有一些输入示例：the street is 4.5 miles longthe budget was 430.000 dollars

Answer 1

str.replace如果可行，我们可以使用您的原始表达式：

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'>" $1_$2 "</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'>" $1_$2 "</span>`;

// The substituted value will be contained in the result variable

const result = str.replace(regex, subst);

console.log(result);

演示

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regex101.com 上的此链接。

正则表达式电路

jex.im可视化正则表达式：

Answer 2

为您提供更简单更清晰的示例

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)