java: use StringBuilder to insert at the beginning

Question

I could only do this with String, for example:

String str=\"\";
for(int i=0;i<100;i++){
    str=i+str;
}

Is there a way to achieve this wit

Answer 1

You can use the insert method with the offset. as offset set to '0' means you are appending to the front of your StringBuilder.

StringBuilder sb = new StringBuilder();
for(int i=0;i<100;i++){
    sb.insert(0,i);
}

NOTE: as the insert method accept all types of primitives, you can use for int, long, char[] etc.