Printing multiple characters from a string

Question

If I have a string "SSSAAADDDCCC" how would I print just "SADC". Can it be done using SubString or would I have to use charAt()?

Answer 1

There is a simple way to do this - however since I don't see any code and I do not see any effort on your part I will not just give you the answer. Below is some psudo code you can work off to try to find the right answer. Good Luck!

currentChar = myString.charAt(0);
i = 0;
print current character //as per comments, cover the base case
while(string has more characters)
    if current character != next character
       print next character
    i++

Answer 2

Use regular expression to replace all repeating characters with a single character:

"SSSAAADDDCCC".replaceAll("(.)\\1+", "$1")   // returns "SADC"

(.) matches and captures a character.
\\1+ matches one or more instances of the captured character.
$1 replaces the entire matched value with the captured character.

Non-repeating characters are not matched, and are therefore left alone.

Answer 3

If you don't like the charAt method you could use substrings like this:

int j=0;
String in="sssdddaaaccc";
String out="";
for(int i=0;i<4;i++)
{
    out=out+in.subString(j,j+1);
    for(j=j; j<3;j++);
}
System.out.println(out);