JEP 326 Raw string literals provide a new way to declare strings without escape characters or unicode escapes. Let's take a look at the example below that declares multi-line strings with JDK 12 and prior releases.

To print all the days in a week with new lines, here is how we do it with the current JDK 11 release:

 String daysInAWeekStr = "Days in a week \n" +
                                "\t\t\tSunday\n" +
                                 "\t\t\tMonday\n" +
                                "\t\t\tTuesday\n" +
                                "\t\t\tWednesday\n" +
                                 "\t\t\tThursday\n" +
                                 "\t\t\tFriday\n" +
                                 "\t\t\tSaturday\n";
System.out.println(daysInAWeekStr);

This is what it will look like in JDK 12:

String daysInAWeekStr = `Days in a week
                                Sunday
                                 Monday
                                 Tuesday
                                 Wednesday
                                 Thursday
                                 Friday
                                 Saturday`;

System.out.println(daysInAWeekStr);

Notice "`" characters to define the string variable. It avoids backslashes to escape unicode characters,\n new lines, and avoid "+" appending strings. It also increases the readability by avoiding leaning toothpick syndrome.

Output:

java --enable-preview <class>
Days in a week 
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday

This feature is now (as of writing this blog) available as a preview feature in JDK 12 early access builds. In order to enable this use, pass the --enable-preview argument.

For more JDK 12 features scheduled in March 2019, click here. This list is not complete and more features might be added. We have to wait until Dec 2018 for the exhaustive list.