Question

Currently in my code I have something in a for loop similar to:

bstr = bstr + x.charAt(i) + x.charAt(i>>4) + x.charAt(i>>8);

Where i is an integer and the loop variable and x is a static final constant string of characters. bstr could be in the order of KBs.

Thanks

Answer 1

A performant way to do this is to use a StringBuilder to concatenate your string:

StringBuilder builder = new StringBuilder();
for(int i = 0; i < count; i++){
    builder.append(x.charAt(i));
    builder.append(x.charAt(i>>4));
    builder.append(x.charAt(i>>8));
}

return builder.toString();

This technique avoids the problem of storing all the copies of Strings between concatentations across the for loop.

edit:

or does this work for you (without adding chars one at a time):

StringBuilder builder = new StringBuilder();
for(int i = 0; i < count; i++){
    builder.append(x);
}

return builder.toString();