How to Remove substring from string

Question

I wan't to remove Y from X and this compiles, however when I run it in my main method I get an error saying out of bounds. I am unsure what is wrong. any help would be appreciated.

public static String filter(String X, String Y) {
    String i = X;
    if ((X != null) && (X.length() >0) && (Y != null) &&Y.length() >0 && (i !=null)){
        int z = X.indexOf(Y);
        i = X.substring(0, z) +X.substring(z + Y.length());
    }
    return i;
}

most probably `indexOf` is giving you `-1` because `y` is not present in `x` — singhakash, Apr 06 '15 at 06:25

score 1 · Answer 1 · edited Apr 06 '15 at 06:35

1

As @singhakash already pointed out that

int z = X.indexOf(Y); --> this is returning -1

So

X.substring(0, z)

become

X.substring(0, -1)

causing OutOfBounds Exception

P.S. Why have you complicated it so much !! Instead you can use String#replace or String#replaceAll

String X="StackOverflow";
String Y="flow";
X=X.replaceAll(Y,"");
System.out.println(X);

Output

StackOver

Demo1- if y is not present in x you get index out of bound

Demo2- if y is present in x you will get correct output

edited Apr 06 '15 at 06:35

singhakash

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answered Apr 06 '15 at 06:29

Neeraj Jain

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I need to do it without using replace. I know how much easier it would be. – Nate Helfenberger Apr 06 '15 at 06:31
then probably you should check that , Y exists or not in X ...!! – Neeraj Jain Apr 06 '15 at 06:32

score 1 · Answer 2 · answered Apr 06 '15 at 06:32

1

Use replaceAll method

public static String filter(String X, String Y) {
    return X.replaceAll(Y,"");
}

answered Apr 06 '15 at 06:32

Sumit Singh

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score 1 · Answer 3 · answered Apr 06 '15 at 06:36

1

I guess this will work for you :

if((x !=null && y !=null) && x.contains(y)) {
   System.out.println(x.replaceAll(y, ""));
}

answered Apr 06 '15 at 06:36

Balaji

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score 0 · Answer 4 · answered Apr 06 '15 at 06:29

0

The Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -1 occurs when the length of string X is less than string Y because of this X.substring(z + Y.length())

Have a additional check for "X.length() > Y.length()" and it should work fine.

answered Apr 06 '15 at 06:29

Raghava Rudrakanth P V

131
5

I added the extra check and it still errors out, do you have any other suggestions? – Nate Helfenberger Apr 06 '15 at 06:35
Can you please share the sample input that is used for your testing. Below is the code snippet. `public static String filter(String X, String Y) { String i = X; if ((X != null) && (X.length() >0) && (Y != null) &&Y.length() >0 && (i !=null) && (X.length() > Y.length())) { int z = X.indexOf(Y); i = X.substring(0, z) +X.substring(z + Y.length()); } return i; }` – Raghava Rudrakanth P V Apr 06 '15 at 06:52

TheCurious · Answer 5 · 2015-04-06T06:48:05.733

If You want to remove all occurrence of Y in X use the following code.

public static String filter(String X, String Y) {
if ((X != null) && (X.length() >0) && (Y != null) &&Y.length() >0) {
while(X.contains(Y)){
int z = X.indexOf(Y);
X = X.substring(0, z) +X.substring(z + Y.length());
}}
return X;

also if X does not contain Y then int z = X.indexOf(Y); --> this is returning -1 X.substring(0, z) ie X.substring(0, -1)-->causing OutOfBounds Exception

It is better to use X=X.replaceAll(Y,"");

score -1 · Answer 6 · answered Apr 06 '15 at 06:25

-1

You can use this:

String subString = testString.subString(firstIndex, secondIndex);

and you can get the index by this:

int index = testString.indexOf(String);

answered Apr 06 '15 at 06:25

RJB

32
8

OP is already using both of the methods you suggested, so what's your point? – Robby Cornelissen Apr 06 '15 at 06:26
I can run this from method call but as soon as i try my main method it errors out. – Nate Helfenberger Apr 06 '15 at 06:28
You can check if Y is in X by doing this: X.contains(Y); – RJB Apr 06 '15 at 06:30

How to Remove substring from string

6 Answers6