crawdad:programming:operators

There are several different types of operations available in C/C++:

** Arithmetic**:

Operator | Action |
---|---|

= | Assignment |

+ | Addition |

- | Subtraction |

* | Multiplication |

/ | Division |

% | Modulo (remainder after division) |

+= | Add then assign |

-= | Subtract then assign |

*= | Multiply then assign |

/= | Divide then assign |

++ | Increment |

-- | Decrement |

Examples:

- y = x : Copy the value of x into y.
- y = m * x + b : m*x is evaluated first, the result of which is added to the value of b. The final result is assigned to y.
- y = m * (x + b) : x+b is evaluated first, the result of which is multiplied by m. The final result is assign to y.
- iter++ : increment the value of iter by one.
- energy *= 4.0 : Multiply the value of energy by 4.0.
- memleft = memory % size : The value of memleft is assigned to the remainder after dividing memory by size;

** Boolean/Comparision**: Return zero (0) if false and any other value if true.

Operator | Action |
---|---|

== | Equal to |

!= | Not equal to |

> | Greater than |

< | Less than |

>= | Greater than or equal to |

⇐ | Less than or equal to |

Example:

- y == x : Returns true if the values stored in y and x are exactly the same and false otherwise. (Be careful about the distinction between “==” and “=”!)

** Logical**:

Operator | Action |
---|---|

&& | And |

|| | Or |

! | Not |

Examples:

- x == y && a == b : Returns true if the values stored in x and y are identical AND the values stored in a and b are identical.
- x == y || a == b : Returns true if the values stored in x and y are identical OR the values stored in a and b are identical.

crawdad/programming/operators.txt · Last modified: 2009/08/05 18:43 by mactay