##### Cheat Sheet

# C All-in-One Desk Reference For Dummies Cheat Sheet

When working in the C programming language, you need to be familiar with how C does things — for example, its order of precedence, variable types, operators, and comparisons and their opposites.

## Order of Precedence in C Programming Language

If you’re programming with C, you’re using operators — and knowing whether to read those operators from left to right or right to left means writing a C program that works and one that crashes. Use the information in the following table to determine the order of precedence in C:

## C Language Variable Types

Whether you’re working with regular or unsigned variables in your C program, you need to know a bit about those various variables. The following table show C variable types, their value ranges, and a few helpful comments:

## C Language Operators

In programming with C, you occasionally want to use common mathematical operators for common mathematical functions and not-so-common operators for logic and sequence functions. Here’s a look at C language operators to use:

Operator, Category, Duty | Operator, Category, Duty | Operator, Category, Duty |
---|---|---|

=, Assignment, Equals | !=, Comparison, Is not equal to | >, Bitwise, Shift bits right |

+, Mathematical, Addition | &&, Logical, AND | ~, Bitwise, One’s complement |

–, Mathematical, Subtraction | ||, Logical, OR | +, Unary, Positive |

*, Mathematical, Multiplication | !, Logical, NOT | –, Unary, Negative |

/, Mathematical, Division | ++, Mathematical, Increment by 1 | *, Unary, Pointer |

%, Mathematical, Modulo | –, Mathematical, Decrement by 1 | &, Unary, Address |

>, Comparison, Greater than | &, Bitwise, AND | sizeof, Unary, Returns the size of an object |

>=, Comparison, Greater than or equal to | |, Bitwise, Inclusive OR | ., Structure, Element access |

<, Comparison, Less than | ^, Bitwise, Exclusive OR (XOR or EOR) | ->, Structure, Pointer element access |

<=, Comparison, Less than or equal to | <<, Bitwise, Shift bits left | ?:, Conditional , Funky if operator expression |

==, Comparison, Is equal to |

## C Language Comparisons and Their Opposites

Programming in C, or any programming language, means building comparisons — greater and lesser than and equal to in various combinations. Get to know the comparisons C uses and their opposites:

If Comparision | Else Statement Executed By | This Condition |
---|---|---|

< | >= | Greater than or equal to |

== | != | Not equal to |

> | <= | Less than or equal to |

<= | > | Greater than |

>= | < | Less than |

!= | == | Equal to |