added some info about System.out.printf() method (#22070)

printf() method uses a stringbuilder wich is more efficient in memory

guide/english/java/strings/index.md

@@ -69,6 +69,10 @@ public class StringExample{
    }
 }
 ```
+If you want to print a string with values in Java it is better to use the following:
+   System.out.printf("example text with %s",value); //where value is a parameter
+   
+This uses the StringBuilder Class wich is more efficient for memory.
 
 Output:
 ```