Thread: class String replaceAll does not behave as i expected

The situation : I have a string and if a word is considered to be a mistake it has to be replaced by "SPELLING_MISTAKE".How do i resolve if a word is a mistake or not?I have a string array with all the correct words.So when i trace the wrong word the progam behaves good and reaches the line where the replacement is meant to be done.But no replacement is done :/ Why?What i am missing?

package essaycorrection;
 
public class Phrase {
 
    /**
     * **************************Variables-fields****************************
     */
    private int noOfWords;
    private String content;
    private static final String[] correctWords = {"All", "Work", "And", "No", "Play",
        "Makes", "Jack", "A", "Dull", "Boy"};
    private static final String[] wrongWords = {"Samaras", "Theodor", "George", "Kostoula",
        "Charalampos", "Pokemon", "Lapras", "Kahn", "Charizard", "Skoupi"};
 
    /**
     * **************************Constructor****************************
     */
    public Phrase(int N) {
        content = "";
        noOfWords = 1 + (int) (Math.random() * N);//numbers from [1,N]
        int select;//pick correct or wrong word
        for (int i = 0; i < noOfWords; i++) {
            select = (int) (Math.random() * 2);
            if (select == 1) {
                content += correctWords[(int) (Math.random() * noOfWords)] + " ";
            } else {
                content += wrongWords[(int) (Math.random() * noOfWords)] + " ";
            }
        }
        System.out.println("I just composed a phrase with content : " + content + ".");
    }
 
    /**
     * **************************Accessors****************************
     */
    public int getNoOfWords() {
        return noOfWords;
    }
 
    public String getContent() {
        return content;
    }
 
    public String[] getCorrectWords() {
        return correctWords;
    }
 
    public String[] getWrongWords() {
        return wrongWords;
    }
 
    /**
     * **************************Methods****************************
     */
    void spellCorrect() {
        String temp = "";//holds a word at the time in order to check the correctness
        char letter;
        boolean mistake;
        int i = 0;
        while (i < content.length()) {
            if ((letter = content.charAt(i)) != ' ') {
                temp += letter;
            } else {
                mistake = true;
                for (int j = 0; j < correctWords.length; j++) {
                    if ((temp.compareToIgnoreCase(correctWords[j])) == 0) {
                        mistake = false;
                    }
                }
                if (mistake) {System.out.println("edw1 "+temp );
                    content.replaceAll(temp, "SPELLING_MISTAKE");
                }
                temp="";
            }
            i++;
        }
 
    }
 
    public void print()
    {
        System.out.println(content+".");
    }
}

in main

        Phrase p = new Phrase(5);
        p.spellCorrect();
        p.print();

and the output

I just composed a phrase with content : Samaras Samaras Samaras .
edw1 Samaras
edw1 Samaras
edw1 Samaras
Samaras Samaras Samaras .
BUILD SUCCESSFUL (total time: 0 seconds)

Also tried replaceFirst but no change in output!

@Norm i wrote the lines of main that are invoke the method
@Zaphod_b the answer was Strings are immutable ( unlike the StringBuilder Class).Hitting stop run was also needed.I am going to fix it now!Thank you both.

PS-Zaphod_b your name is awesome ,it reminds me of Zapdos(this is a pokemon ) from when i was a kid.

Originally Posted by Samaras

I am going to fix it now!

Solved! I post it in order other people face the same problem

void spellCorrect() {
        String temp = "";//holds a word at the time in order to check the correctness
        char letter;
        boolean mistake;
        int i = 0;
        while (i < content.length()) {
            if ((letter = content.charAt(i)) != ' ') {
                temp += letter;
            } else {
                mistake = true;
                for (int j = 0; j < correctWords.length; j++) {
                    if ((temp.compareToIgnoreCase(correctWords[j])) == 0) {
                        mistake = false;
                    }
                }
                if (mistake) {
                    content=content.replaceAll(temp, "SPELLING_MISTAKE");
                    while ((letter = content.charAt(i)) != ' ') {
                        i++;
                    }
                }
                temp="";
            }
            i++;
        }
 
    }

Originally Posted by Norm

Where is the main() method for testing? I don't see where the code is that can be compiled for testing.
Can you provide one for testing?

Oh,i did that in order not to make you tired of reading code.I solve it now

Originally Posted by Norm

That's fine if you don't want anyone to help by compiling and testing the code.

All i wanted is to make your life easier :/ I understand that i did not succeed in it.Now you told i'll keep that in mind