This C Tutorial explains Escape Sequences/Character Escapes and why they are needed.
One or more characters following ‘\’ (the backslash) is considered to be a single character and is called the escape sequence. For example:
\? used to write multiple question marks from being interpreted as trigraphs in printf() statements
\” used to get the quotation marks inside the string literals
\’ used to write a character literal for a character
\\ used to write a backslash from being interpreted as a character escape
\a \b etc.
Escape sequences are used in a program to override the special meaning of characters in particular contexts! For example:
printf("What is your name? Are you \"some Xyz\"?"); /* * OUTPUT: What is your name? Are you "some XYZ"? * Note the Name in output enclosed in Quotation Marks */
Trigraphs are all three-lettered characters, all begin with ?? (double question marks) followed by a character, represent some other character. Basically, they are used to complement a Character Set lacking for some characters. For example:
??( represent [ ??) represent ]
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