如何替换两个索引之间的子字符串

Question

我想在Javascript中的两个索引之间替换文本,例如:

str = "The Hello World Code!";
str.replaceBetween(4,9,"Hi");
// outputs "The Hi World Code"

索引和字符串都是动态的.

我怎么能这样做？

Answer 1

JavaScript中没有这样的方法.但是你可以随时创建自己的:

String.prototype.replaceBetween = function(start, end, what) {
  return this.substring(0, start) + what + this.substring(end);
};

console.log("The Hello World Code!".replaceBetween(4, 9, "Hi"));

Answer 2

接受的答案是正确的，但我想避免扩展 String prototype：

function replaceBetween(origin, startIndex, endIndex, insertion) {
  return origin.substring(0, startIndex) + insertion + origin.substring(endIndex);
}

用法：

replaceBetween('Hi World', 3, 7, 'People');

// Hi People

如果使用简洁的箭头函数，那么它是：

const replaceBetween = (origin, startIndex, endIndex, insertion) =>
  origin.substring(0, startIndex) + insertion + origin.substring(endIndex);

如果使用模板文字，则为：

const replaceBetween = (origin, startIndex, endIndex, insertion) =>
  `${origin.substring(0, startIndex)}${insertion}${origin.substring(endIndex)}`;

Answer 3

Array.spliceJavaScript中有一种方法可以完成这项工作,但是没有String.splice.但是,如果将字符串转换为数组,则:

var str = "The Hello World Code!";
var arr = str.split('');
var removed = arr.splice(4,5,"Hi"); // arr is modified
str = arr.join('');