javascript - 查找子字符串并插入另一个字符串

Question

假设我有字符串变量，例如:

var a = "xxxxxxxxhelloxxxxxxxx";

或:

var a = "xxxxhelloxxxx";

我想在 "hello" 之后插入 "world"。

我不能使用 substr() 因为无法提前知道位置。我如何在 JavaScript 或 jQuery 中执行此操作？

Answer 1

var a = "xxxxhelloxxxxhelloxxxx";
a = a.replace(/hello/g,"hello world"); // if you want all the "hello"'s in the string to be replaced
document.getElementById("regex").textContent = a;

a = "xxxxhelloxxxxhelloxxxx";
a = a.replace("hello","hello world"); // if you want only the first occurrence of "hello" to be replaced
document.getElementById("string").textContent = a;

<p>With regex: <strong id="regex"></strong></p>
<p>With string: <strong id="string"></strong></p>