Javascript 等价于 python 的 .format()

问题描述

我想要一个模仿 python .format() 函数的 javascript 函数

I would like a javascript function that mimics the python .format() function that works like

.format(*args, **kwargs)

上一个问题为 '.format(*args) 提供了一个可能(但不完整)的解决方案

A previous question gives a possible (but not complete) solution for '.format(*args)

JavaScript 等效于 printf/string.format

我希望能够做到

"hello {} and {}".format("you", "bob"
==> hello you and bob

"hello {0} and {1}".format("you", "bob")
==> hello you and bob

"hello {0} and {1} and {a}".format("you", "bob",a="mary")
==> hello you and bob and mary

"hello {0} and {1} and {a} and {2}".format("you", "bob","jill",a="mary")
==> hello you and bob and mary and jill

我意识到这是一项艰巨的任务，但也许在某个地方有一个完整(或至少部分)的解决方案，其中也包括关键字参数.

I realize that's a tall order, but maybe somewhere out there is a complete (or at least partial) solution that includes keyword arguments as well.

哦，我听说 AJAX 和 JQuery 可能有这方面的方法，但我希望能够在没有所有开销的情况下做到这一点.

Oh, and I hear AJAX and JQuery possibly have methods for this, but I would like to be able to do it without all that overhead.

特别是，我希望能够将它与 google doc 的脚本一起使用.

In particular, I would like to be able to use it with a script for a google doc.

谢谢

推荐答案

更新:如果您使用的是 ES6，模板字符串的工作方式与 String.format 非常相似:https://developers.google.com/web/updates/2015/01/ES6-Template-字符串

UPDATE: If you're using ES6, template strings work very similarly to String.format: https://developers.google.com/web/updates/2015/01/ES6-Template-Strings

如果不是，以下适用于上述所有情况，其语法与 python 的 String.format 方法非常相似.下面是测试用例.

If not, the below works for all the cases above, with a very similar syntax to python's String.format method. Test cases below.

String.prototype.format = function() {
  var args = arguments;
  this.unkeyed_index = 0;
  return this.replace(/{(w*)}/g, function(match, key) { 
    if (key === '') {
      key = this.unkeyed_index;
      this.unkeyed_index++
    }
    if (key == +key) {
      return args[key] !== 'undefined'
      ? args[key]
      : match;
    } else {
      for (var i = 0; i < args.length; i++) {
        if (typeof args[i] === 'object' && typeof args[i][key] !== 'undefined') {
          return args[i][key];
        }
      }
      return match;
    }
  }.bind(this));
};

// Run some tests
$('#tests')
  .append(
    "hello {} and {}<br />".format("you", "bob")
  )
  .append(
    "hello {0} and {1}<br />".format("you", "bob")
  )
  .append(
    "hello {0} and {1} and {a}<br />".format("you", "bob", {a:"mary"})
  )
  .append(
    "hello {0} and {1} and {a} and {2}<br />".format("you", "bob", "jill", {a:"mary"})
  );

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="tests"></div>

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