string.trim() not functional?

Question

It may look a Stupid question, but It is giving wrong output !!

The trim() is supposed to delete the 'space' or 'new line' character at the beginning or end of the String, but it isn't working.

String str=str.getText().toString();
str.trim();
if(str.equalsIgnoreCase("STRING"))
    mytextview.setText("True");
else
    mytextview.setText("False");

If I'm Entering ---> " STRING " (With many spaces ), I am getting False as the Answer .... I'm using Eclipse Juno for my Androing Project, are there any exceptions ? Please Help.

A `String` in java is immutable. It can not be modified. `trim()` returns a new `String`. — Brian Roach, Jul 01 '13 at 17:52

score 5 · Accepted Answer · edited Jul 01 '13 at 18:00

5

String str=str.getText().toString();
str.trim();

should be:

String str=str.getText().toString();
str = str.trim();

Strings are immutable in Java. An operation like trim() creates a new String.

edited Jul 01 '13 at 18:00

Stephen C

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answered Jul 01 '13 at 17:51

kosa

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@user2525485: Looks like Nambari beat all of us to the answer. The best way for this site to help others is select an answer. That way if others view the question they have a clear "correct" answer. You can mark the selected answer by clicking on the checkmark next to Nambari's answer. – Vanquish46 Jul 01 '13 at 17:58

score 2 · Answer 2 · answered Jul 01 '13 at 17:52

2

You are not storing the output of str.trim(). It does not modify the original String; rather, it generates a new, separate one.

You can store it back into the original by using str = str.trim().

answered Jul 01 '13 at 17:52

asteri

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score 1 · Answer 3 · answered Jul 01 '13 at 17:53

1

String.trim() returns the resulting trimmed string.

You need to do str = str.trim();

answered Jul 01 '13 at 17:53

Vanquish46

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score 1 · Answer 4 · answered Jul 01 '13 at 17:55

1

The trim method returns a copy of the string. Change the second line to be:

str = str.trim();

Source: http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#trim()

answered Jul 01 '13 at 17:55

Olivia

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score 1 · Answer 5 · answered Jul 01 '13 at 18:03

1

Use

 String str=str.getText().toString().trim();

answered Jul 01 '13 at 18:03

Ruchira Gayan Ranaweera

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string.trim() not functional?

5 Answers5