How to append a String in Java?

To append a String in Java, use the + operator.

Here's how you do it:

String result = "Hello " + "World!";

System.out.println(result); // Hello World!

Efficiently append multiple times

To efficiently append multiple times, use the StringBuilder:

StringBuilder stringBuilder = new StringBuilder();

stringBuilder.append("Hello");
stringBuilder.append(" ");
stringBuilder.append("World");
stringBuilder.append("!");

String result = stringBuilder.toString();

System.out.println(stringBuilder.toString()); // Hello World!