Escape Sequences:

  • Escape Sequences are used to format the output from a print function.
  • The escapes sequences are character literals or character constants.
  • Every escape sequence character starts with a backward slash(\)
  • Though it is a combination of \ and another letter (two characters), it is treated as a single character.

Escape Sequences in C

Character Name Use
\n New line Move the cursor to next line
\t Tab Space Insert a single Tab Space
\a Alert Generates a Beep Sound
\b Back Space Cursor is moved one character back
\r Carraige Return Cursor moved to starting of the same line
\\ Forward Slash Insert a single \
\" Double quote Insert a single "

Data Types and Format Specifiers:

Variable:

  • Variable is defined to be named memory location
  • A single variable can hold a single data value only
  • If the variable is already having a value an a new value is given, then the new value replaces the old value.
  • Variable named should be chosen by the programmer and should obey identifier rules (Ref Chap-1 Introduction to C)

Data Types:

  • The data type is defined to be a keyword that defines the type of data that a variable can hold.
  • The flow chart below gives a clear view of data types in C:
Data Types in C++


System Defined Data Types

Name Keyword Format Specifier Memory Range
Void void --- 0 bytes Nothing
Character char %c 1 byte Any Ascii Character
Integer int %d 2 bytes -32768 to 32768
Float float %f 4 bytes 3.4*10^-38 to 3.4*10^38
Double double %lf 8 bytes 1.7*10^-308 to 1.7*10^308

Type Qualifiers:

Type Qualifier is a special keyword that can control the basic data to an increased range or to a decreased range slightly.
Data Types in C