?
Solved

String Concat vs. +

Posted on 1998-11-15
1
Medium Priority
?
338 Views
Last Modified: 2011-09-20

What is the difference between the concat() method in String and the '+' operator for the String?  I thought they were the same, but when I try to "build" a string by concatening (using the concat method) strings to an initially empty string, I appear to get nothing, whereas if I do it via '+' (or in this case '+=') it turns out ok.  
Here is the sample code:

String processedString = "";
String workingString = myTextArea.getText();
int stringLength = workingString.length();

     for (int i = 0; i < stringLength; i++){
        if (workingString.charAt(i) == '\n'){
                processedString += "\r\n";
                // Or processedString.concat("\r\n");
            }
            else{
                processedString += workingString.charAt(i);
                // Or processedString.concat("" + workingString.charAt(i));
            }
        }
    }

Thanks for shedding any light on this!


ap9
0
Comment
Question by:ap9
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 4

Accepted Solution

by:
martinag earned 200 total points
ID: 1227491
The concat() function doesn't change the string's value, it just returns a new String object.

processedString = processedString.concat("" + workingString.charAt(i));
should work for you.

Martin
0

Featured Post

Optimize your web performance

What's in the eBook?
- Full list of reasons for poor performance
- Ultimate measures to speed things up
- Primary web monitoring types
- KPIs you should be monitoring in order to increase your ROI

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
Suggested Courses
Course of the Month12 days, 14 hours left to enroll

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question