javascript - 在这种情况下如何替换字符串并获得我需要的内容？

Question

我正在尝试用两组模式替换字符串。例如，

var pattern1 = '12345abcde/';  -> this is dynamic.
var myString = '12345abcde/hd123/godaddy_item' 

我的最终目标是获取两个斜杠之间的值，即hd123

我有

var stringIneed = myString.replace(pattern1, '').replace('godaddy_item','');

上面的代码可以工作，但我认为还有更优雅的解决方案。谁能帮我解决这个问题吗？非常感谢!

更新: 更清楚地说，该模式是针对每个环境字符串的。例如，pattern1 可能类似于:

https://myproject-development/item on development environment.

和

https://myproject/item on Production

myString 通常可能类似于

https://myproject/item/hd123/godaddy_item

或

https://myproject-development/item/hd123/godaddy_item

就我而言，我需要获取“hd123”。

Answer 1

我强烈建议不要为此使用正则表达式，特别是当简单的 String 和 Array 方法就足够了并且更容易理解时，例如:

// your question shows you can anticipate the sections you
// don't require, so put both/all of those portions into an
// array:
var unwanted = ['12345abcde', 'godaddy_item'],

  // the string you wish to find the segment from:
  myString = '12345abcde/hd123/godaddy_item',

  // splitting the String into an array by splitting on the '/'
  // characters, filtering that array using an arrow function
  // in which the section is the current array-element of the
  // array over which we're iterating; and here we keep those
  // sections which are not found in the unwanted Array (the index
  // an element not found in an Array is returned as -1):
  desired = myString.split('/').filter(section => unwanted.indexOf(section) === -1);

console.log(desired); // ["hd123"]

对于不支持 ES6 的浏览器，避免使用箭头函数(并删除了代码注释):

var unwanted = ['12345abcde', 'godaddy_item'],
  myString = '12345abcde/hd123/godaddy_item',
  desired = myString.split('/').filter(function (section) {
   return unwanted.indexOf(section) === -1;
  });

console.log(desired); // ["hd123"]

或者:

// the string to start with and filter:
var myString = '12345abcde/hd123/godaddy_item',

  // splitting the string by the '/' characters and keeping those whose
  // index is greater than 0 (so 'not the first') and also less than the
  // length of the array-1 (since JS arrays are zero-indexed while length
  // is 1-based):
  wanted = myString.split('/').filter((section, index, array) => index > 0 && index < array.length - 1);

console.log(wanted); // ["hd123"]

JS Fiddle demo

但是，如果要找到的必需字符串始终是所提供字符串的倒数第二部分，那么我们可以使用 Array.prototype.filter() 只返回该部分:

var myString = '12345abcde/hd123/godaddy_item',
  wanted = myString.split('/').filter((section, index, array) => index === array.length - 2);

console.log(wanted); // ["hd123"]

JS Fiddle demo .

引用文献:

• Array.prototype.filter() .
• Arrow functions .
• String.prototype.split() .