CODEWITHSUNDEEP
java
user6734995
user6734995

Reputation:

Tabs don't get removed from string

Environment : Windows, Java 1.8 I am reading the content of a file and I try to format the lines and remove the tabs, but replaceAll it's not working.

I tryed with:

    BufferedReader bf = FileUtils.getBufferedReader(filePath);
    String line;

    try {
        while ((line = bf.readLine()) != null )
        {
            if(line.matches(".*=.*"))
            {
                // this is a simple test scenario
                String test = "\tVERSION=version";
                test.trim();
                test.replaceAll("\t", "");

                line.trim();
                line.replaceAll("\\t", "");

            }
        }
    } catch (IOException e) {
        System.err.println("[ERROR] : Could not read from file <" + filePath + ">!\n");
        System.exit(0);
    }

I looked into debugger and the tabs are not replaced. On the test scenario I tried with both \t and \\t variants without success. Am I doing something wrong?

Upvotes: 0

Views: 34

Answers (1)

nos
nos

Reputation: 229158

In Java, a String is immutable - that means you can not change a string, so a method such as String.replaceAll could never change the String object you call that method on.

As noted in the documentation, both String.trim() and String.replaceAll() returns a new, altered, string. That's the string you need to use, and forget about the old string. Your code should look like:

test =  test.trim();
test =  test.replaceAll("\t", "");

line = line.trim();
line = line.replaceAll("\\t", "");

Upvotes: 1

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