Java replace() problems

Question

I'm supposed to input a string, and replace all and, to, you, and for substrings with &, 2, U, and 4.

When I input the string "and , and,and , to , to,to , you ,you , you, for ,for , for,a , a,e , e,i , i,o , o,u , u", it only outputs and when I print it.

public void simplify()
{
 System.out.println("Enter a string to simplify: ");
 String rope = in.next();
 System.out.println(simplifier(rope));
}
public String simplifier(String rope)
{
 rope = rope.replace(" and "," & ");
 rope = rope.replace(" and"," &");
 rope = rope.replace("and ","& ");
 rope = rope.replace(" to "," 2 ");
 rope = rope.replace(" to"," 2");
 rope = rope.replace("to ","2 ");
 rope = rope.replace(" you "," U ");
 rope = rope.replace("you ","U ");
 rope = rope.replace(" you"," U");
 rope = rope.replace(" for "," 4 ");
 rope = rope.replace("for ","4 ");
 rope = rope.replace(" for"," 4");
 rope = rope.replace("a ","");
 rope = rope.replace(" a","");
 rope = rope.replace("e ","");
 rope = rope.replace(" e","");
 rope = rope.replace("i ","");
 rope = rope.replace(" i","");
 rope = rope.replace(" o","");
 rope = rope.replace("o ","");
 rope = rope.replace("u ","");
 rope = rope.replace(" u","");
 System.out.print(rope);
 return rope;
}

Output:and and

It seems to cut off the returned string after the first space

I have no idea what is going on and why it is not working as it should. What am I doing wrong?

• M A: "why it is not working as it should". What should it output?
• Christophe De Troyer: Write the string down on paper. Manually replace everything. You'll see.. replaceAll replaces all the text from the first parameter with the text from the second parameter. Read docs.oracle.com/javase/7/docs/api/java/lang/String.html for information.
• Eran: You should note that you are passing an argument to the method, but overwrite it inside the method with another String. Perhaps that's causing your confusion.
• Eran: Your method (after closing the String literal in the first line), returns & , &,& , 2 , 2,2 , U ,U , U, 4 ,4 , 4,,,,,,,,,,
• Stanislav: @James you have to provide the code, which uses this method, because simplifier() returns exactly what you need

Answer 1

Here is how I simplified your code and got the correct result:

 String rope = "and , and,and , to , to,to , you ,you , you, for ,for , for,a , a,e , e,i , i,o , o,u , u";
 // rope = rope.replaceAll(" ", "");
 rope = rope.replaceAll("and", "&");
 rope = rope.replaceAll("to", "2");
 rope = rope.replaceAll("you", "U");
 rope = rope.replaceAll("for", "4");
 rope = rope.replaceAll("a", "");
 rope = rope.replaceAll("e", "");
 rope = rope.replaceAll("i", "");
 rope = rope.replaceAll("o", "");
 rope = rope.replaceAll("u", "");
 System.out.println(rope);

• James: Thank you for your help, this worked for me. Thanks :)
• Arash: @James glad it helped :) Please choose my answer or vote up, so I can work better to help others

Answer 2

Replace the first rope = rope.replace(" and "," & "); with rope = rope.replace("and "," & ");

Now it should work. The problem was that the first "and" you were trying to replace was and, not and, which is why that was left and did not get replaced.

Also remove the second last line of simplifier, which is System.out.print(rope);. This is duplicate as you are already printing the result in the calling method.

---

UPDATE: I see what you are trying to do here. Try this:

For each word that you want to replace, replace it only once. So for and, do:

rope.replace("and", "&");

For to, do:

rope.replace("to", "2");

DO NOT add any space between the words, it is not necessary. Doing replace() once will replace ALL occurrences of that word.

• James: It Doesn't seem to work, when i inputted and asdfasdf, it still outputted and and
• James: I tried your suggestion, and it still did not work. It seems as the return method stops when it meets a white space in the string, beause when i inputted and hello, it returned &, and when i inputted ` and hello, and` got returned