Question

I have a string like :

string = abcdefghabcd

Now lets say I want to replace the first occurrence of a. I tried something like this :

string[string.indexOf('a')] = '0'

But this doesn’t seems to be working. Any other way I can do this?

Thanks in advance.

Answer 1

In Java you can use String.replaceFirst() :

String s = "abcdefghabcd";
s = s.replaceFirst("a", "0");
System.out.println(s);

Output will be :

0bcdefghabcd

Warning : the replaceFirst() method takes a regex : so if you want to replace a special character like [ you need to escape by putting a \ before it. \ being a special character itself, you need to double it as follow :

s = s.replaceFirst("\\[", "0");

Here is the documentation on Java Regular Expressions. Also, here is Oracle’s Java tutorial on manipulating Characters in Strings.