String replaceAll not replacing i++;

Question

String preCode = "helloi++;world";
String newCode = preCode.replaceAll("i++;", "");

// Desired output :: newCode = "helloworld";

But this is not replacing i++ with blank.

Navneet Krishna · Accepted Answer · 2018-08-06T12:30:54.893

8

just use replace() instead of replaceAll()

String preCode = "helloi++;world";
String newCode = preCode.replace("i++;", "");

or if you want replaceAll(), apply following regex

String preCode = "helloi++;world";
String newCode = preCode.replaceAll("i\\+\\+;", "");

Note : in the case of replace() the first argument is a character sequence, but in the case of replaceAll the first argument is regex

edited Aug 06 '18 at 12:30

answered Aug 06 '18 at 08:46

Navneet Krishna

5,009
5
25
44

"this is helpfull if you have multiple occurances of character to be replaced" - The only difference between the two function is that one uses regex and the other uses string literals. Both their description starts with "Replaces each substring of this string that matches..." – Simon Kraemer Aug 06 '18 at 12:20
`java.util.regex.Pattern.quote(java.lang.String)` will prevent you from making mistakes when converting a string literal to a regex. – Simon Kraemer Aug 06 '18 at 12:21
thanks for the suggestion, i have updated the answer now – Navneet Krishna Aug 06 '18 at 12:24

Machhindra Neupane · Answer 2 · 2018-08-07T02:03:47.890

3

try this one

 public class Practice {
 public static void main(String...args) {
 String preCode = "Helloi++;world";
 String newCode = preCode.replace(String.valueOf("i++;"),"");
 System.out.println(newCode);
}  
}

edited Aug 07 '18 at 02:03

answered Aug 06 '18 at 09:04

Machhindra Neupane

679
7
20

1

What would you need `String.valueOf("i++")` for? Just using `i++;` should be sufficient. Also you are missing the semicolon. – Simon Kraemer Aug 06 '18 at 12:17
Or you could do `"i++;".toString()`. – shmosel Aug 07 '18 at 02:05

score 2 · Answer 3 · answered Aug 06 '18 at 09:10

2

The problem is the string that you are using to replace , that is cnsidered as regex pattern to skip the meaning you will have to use escape sequence like below.

String newCode = preCode.replaceAll("i\\+\\+;", "");

answered Aug 06 '18 at 09:10

Krishna Satwaji Khandagale

2,235
16
25

String replaceAll not replacing i++;

3 Answers3