After all, the compiler doesn't know \ as anything other than a control sequence! It expects the backslash to be followed by a certain character that it must somehow interpret in a special way (such as a quotation mark).īut, in this case, \ is followed by ordinary letters. Once again, the compiler doesn't understand what to do. String workFiles= new String ("My work files are in D:\Work Projects\java") Suppose we want to tell someone about our work: Quotation marks are by no means the only characters we may need to escape. Let's try running the main() method.Ĭonsole output: My favorite book is "Twilight" by Stephanie MeyerExcellent! The code worked exactly how we wanted it to! We've used \ to escape our two "internal" quotation marks. String myFavoriteBook = new String ("My favorite book is \"Twilight\" by Stephanie Meyer") Let's try changing our code with the book: Upon encountering this construct in your code, the compiler will understand that this is just a quotation mark that should be displayed on the screen. In Java, a backslash combined with a character to be "escaped" is called a control sequence.įor example, \" is a control sequence for displaying quotation marks on the screen. This symbol is normally called "backslash". This is accomplished using a special symbol: \. To do this, Java uses character escaping. We need to let the compiler know when a quotation mark is a command ("create a string!") and when it is simply a character ("display the word "Twilight" along with quotation marks!"). "Another quotation mark? Is this some kind of mistake? I'm already creating a string! Or should I create another one? Argh!.:/" Here's why: simply speaking, the compiler gets confused about what it is expected to do. But that's what the compiler is already doing! The quotation mark suggests that a string must be created. When the compiler reaches this piece of text, it simply doesn't understand what it is expected to do. In our case, the quotation marks around the word "Twilight" are inside other quotation marks. And every time the compiler sees ", it expects that the quotation mark will be followed by a second quotation mark, and that the content between them is the text of a string to be created by the compiler. it expects strings to be wrapped in them. The compiler interprets quotation marks in a very specific way, i.e. What do you think the problem could be? And what does it have to do with quotation marks? It seems the compiler is unhappy about something! String myFavoriteBook = new String ("My favorite book is "Twilight" by Stephanie Meyer") I'm 20!") īut what do we do if we need to create a string that itself must contain quotation marks? For example, suppose we want to tell the world about your favorite book: String alex = new String ("My name is Alex. The main thing when creating a string is that the entire sequence must be enclosed in quotation marks: These characters can be any letters, numerals, punctuation marks and so on. So escape sequences are formed using two things: the first is a backslash (\\), and the second is the set of one or more characters following that backslash (\\).Hi! In previous lessons, we've already gotten acquainted with text strings, which are represented by the String class in Java.Īs you probably remember, a string is a sequence of characters. A sequence is just a set of two or more characters and an escape where the sequence begins with a backslash (\\) and other characters in the set follow that backslash.Īn escape sequence is a sequence of characters that, when used inside a character or string, does not represent itself but is converted into another character or series of characters. So here comes the role of escape sequences.įirstly, understand sequences. Suppose you have the string containing a double backslash (\\\\), and you want to print the string with a double backslash, but it is impossible to print it directly. Introduction to Escape Sequence in Python This character serves as an escape sequence initiator, and every character (one or more) following it is considered an escape sequence. In the escape sequence, a character is preceded by a backslash (\) followed by the character you want to represent for the new line. An escape sequence is a sequence of characters that, when used inside a character or string, does not represent itself but is converted into another character or series of characters that may be difficult or impossible to express directly, like newline (\n), tab (\t), and so on.
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