How do you combine all the strings into a single string?

Question

Running this code:

for(int i = 0 ; i <= 5 ; i++) {
    String id = driver.findElement(By.xpath("//[@id='selectpatientid_" + i + "']")).getText();
    System.out.println(id);
}

The output is set of strings:

vil00043
vil00032
vil00054
vil00032

How can I merge and store all these strings into a single string?

concat the id into one string var and print that outside the loop. — Zia, Jan 05 '16 at 11:42
Would be good if you could choose a correct answer so that question is closed. — Aaditya Gavandalkar, Jan 05 '16 at 14:34

Zia · Accepted Answer · 2016-01-17T18:29:20.017

First approach would be to use String.concat() as below,

 String str="";
 String id ="";
    for(int i=0;i<=5;i++){
        id = driver.findElement(By.xpath("//[@id='selectpatientid_"+i+"']")).getText();
    str.concat(id);
       }
    System.out.println(str);

But the above approach causes multiple String creations. I suggest to go for StringBuilder,

StringBuilder finalStringb =new StringBuilder();
String id ="";
        for(int i=0;i<=5;i++){
            id = driver.findElement(By.xpath("//[@id='selectpatientid_"+i+"']")).getText();
        finalStringb.append(id);
           }
        System.out.println(finalStringb);

Note--`The concat() method of String class takes the string as parameter, it appends the specified string, and returns a new String. Actually,this concat() method creates a new char array for both strings, and then put both strings into the new array, and then again creates a new String with that array.Its degrade the performance. StringBuilder works more efficent. in short if you are useing String concatenation in a loop then you can go with StringBuilder (not StringBuffer) instead of a String, because it is much faster and consumes less memory.

if you took the last paragraph from this answer word for word, you should attribute that answer, otherwise I'll have to delete this. http://stackoverflow.com/questions/4645020/when-to-use-stringbuilder-in-java/4645147#4645147 — George Stocker, Jan 17 '16 at 18:16

How do you combine all the strings into a single string?

1 Answers1