Insert a string at a specific index

Question

How can I insert a string at a specific index of another string?

 var txt1 = \"foo baz\"

Suppose I want to insert \"bar \" after the \"foo

Answer 1

You can use Regular Expressions with a dynamic pattern.

var text = "something";
var output = "                    ";
var pattern = new RegExp("^\\s{"+text.length+"}");
var output.replace(pattern,text);

outputs:

"something      "

This replaces text.length of whitespace characters at the beginning of the string output. The RegExp means ^\ - beginning of a line \s any white space character, repeated {n} times, in this case text.length. Use \\ to \ escape backslashes when building this kind of patterns out of strings.