Manually merge #1780

fixes #1780

java.html.markdown

@@ -8,6 +8,7 @@ contributors:
     - ["Zachary Ferguson", "http://github.com/zfergus2"]
     - ["Cameron Schermerhorn", "http://github.com/cschermerhorn"]
     - ["Rachel Stiyer", "https://github.com/rstiyer"]
+    - ["Michael Dähnert", "http://github.com/JaXt0r"]
 filename: LearnJava.java
 ---
 
@@ -171,6 +172,29 @@ public class LearnJava {
         System.out.println(barString);
         System.out.println(bazString);
 
+        // String Building
+        // #1 - with plus operator
+        // That's the basic way to do it (optimized under the hood)
+        String plusConcatenated = "Strings can " + "be concatenated " + "via + operator.";
+        System.out.println(plusConcatenated);
+        // Output: Strings can be concatenated via + operator.
+
+        // #2 - with StringBuilder
+        // This way doesn't create any intermediate strings. It just stores the string pieces, and ties them together
+        // when toString() is called.
+        // Hint: This class is not thread safe. A thread-safe alternative (with some impact on performance) is StringBuffer.
+        StringBuilder builderConcatenated = new StringBuilder();
+        builderConcatenated.append("You ");
+        builderConcatenated.append("can use ");
+        builderConcatenated.append("the StringBuilder class.");
+        System.out.println(builderConcatenated.toString()); // only now is the string built 
+        // Output: You can use the StringBuilder class.
+
+        // #3 - with String formatter
+        // Another alternative way to create strings. Fast and readable.
+        String.format("%s may prefer %s.", "Or you", "String.format()");
+        // Output: Or you may prefer String.format().
+ 
         // Arrays
         // The array size must be decided upon instantiation
         // The following formats work for declaring an array