I am working with some Java code. Basically I have a wrapper class that holds a string and implements some of the many useful python string methods in Java. My goal here is to implement the Python method .ljust and my hope is to be as efficient as possible. Currently, I am using a while loop which I imagine is terrible inefficient especially because it includes a +=. What's more, I am not sure which of the following alternatives is more efficientString news = ;news = this.toString();int length = news.length();while (length < size) {        news +=  ;        length++;}return new PythonString(news);In the above case, news.length() is only called once, but now there is an extra int and a new instruction length++.The other option would beString news = ;news = this.toString();while (news.length() < size) {        news +=  ;}return new PythonString(news);In this case, news.length() is called every time. I am interested in perspectives on which of these alternatives is most efficient as well as any other optimizations you could provide for this method, which is meant to pad a string with size spaces to the right so that all following characters line up at the same column. 
Java String iterations
java;python;strings;iteration
I am interested in perspectives on which of these alternatives is most efficientUsing StringBuilder in the loop instead of += will likely be far faster than either of your current approaches, especially as size - length gets big. I'm not sure how much more space it would take.