ATSWL - Append To String Within a Loop

Performance enhancements can be obtained by replacing String operations with StringBuffer operations if a String object is appended to within a loop.

Wrong

public class ATSWL {
    public String func () {
        String var = "var";
        for (int i = 0; i < 10; i++) {
            var += (" " + i);
        }
        return var;
    }
}

Tip: Use StringBuffer class instead of String

Right

public class ATSWL {
    public String func () {
        StringBuffer var = new StringBuffer("var");
        for (int i = 0; i < 10; i++) {
            var.append(" " + i);
        }
        return var.toString();
    }
}