javascript - 用计数器升序替换所有特定字符？

Question

我有这样一个字符串:

var str = "some text is here
            - first case
            - second case 
            - third case
           some text is here";

现在我需要这个输出:

var newstr = "some text is here
                1. first case
                2. second case 
                3. third case
               some text is here";

---

我能做的就是removing those - .现在我需要用动态数字替换 $1...这可能吗？

像这样:

.replace (/(^\s*-\s+)/gm, "{A dynamic number which is ascending}. ")

Answer 1

您可以使用 String#replace带有回调和计数器。

使用 ES2015 Arrow function :

str.replace(/^\s*- /gm, () => counter++ + '. ');

var str = `some text is here
                - first case
                - second case 
                - third case
               some text is here`;

var counter = 1;
str = str.replace(/^\s*- /gm, () => counter++ + '. ');

console.log(str);
document.write(str); // Demo purpose

ES5 中的等效代码

str.replace(/^\s*- /gm, function() {
    return counter++ + '. ';
});

正则表达式 /^\s*-/gm 将匹配所有以任意数量的空格开头后跟连字符的行。

var str = `some text is here
            - first case
            - second case 
            - third case
           some text is here`;

var counter = 1; // Initialize the counter

str = str.replace(/^\s*- /gm, function() {
  return counter++ + '. '; // Incrementing counter after using its value
});

console.log(str);
document.write(str); // Demo purpose