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Full Discussion: Arrays in C++
Top Forums Programming Arrays in C++ Post 302584573 by John Tate on Friday 23rd of December 2011 05:03:25 PM
Old 12-23-2011
Arrays in C++
I've noticed something interesting in C++ programming. I've always done tricky stuff with pointers and references to have functions deal with arrays. Doing exercises again out of a C++ book has shown me an easier way, I didn't even know was there. It's weird to me.

When dealing with arrays, it seems if I pass an array to a function although I cannot return an array - if the array is changed it changes for the whole program. The array is seemingly global. Hence this code works (GCC 4.7)...

Code:
#include <iostream>

using namespace std;

int read_inputs(double inputs[], int capacity) {
    int current_size = 0;
    cout << "Please enter values, Q to quit:"<<endl;
    bool more = true;
    while (more)
    {
        double input;
        cin >> input;
        if (cin.fail()) {
            more = false;
        } else if (current_size < capacity) {
            inputs[current_size] = input;
            current_size++;
        }
    }
    return current_size;
}

void multiply(double values[], int size, double factor)
{
    for (int i = 0; i < size; i++)
    {
        values[i]=values[i] * factor;
    }
}

void print(double values[], int size)
{
    for (int i = 0; i < size; i++)
    {
        if (i > 0) {cout << ", ";}
        cout << values[i];
    }
    cout << endl;
}

int main() {
    const int CAPACITY = 1000;
    double values[CAPACITY];
    int size = read_inputs(values, CAPACITY);
    print(values, size);
    multiply(values, size, 2);
    print(values, size);

    return 0;
}

 

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LEARN ABOUT PHP

array_diff

ARRAY_DIFF(3)								 1							     ARRAY_DIFF(3)

array_diff - Computes the difference of arrays

SYNOPSIS

       array array_diff (array	$array1, array	$array2, [array  $...])

DESCRIPTION

	Compares $array1 against one or more other arrays and returns the values in $array1 that are not present in any of the other arrays.

PARAMETERS

	      o $array1
		- The array to compare from

	      o $array2
		- An array to compare against

	      o $...
		- More arrays to compare against

RETURN VALUES

	Returns an array containing all the entries from $array1 that are not present in any of the other arrays.

EXAMPLES

       Example #1

	      array_diff(3) example

	      <?php
	      $array1 = array("a" => "green", "red", "blue", "red");
	      $array2 = array("b" => "green", "yellow", "red");
	      $result = array_diff($array1, $array2);

	      print_r($result);
	      ?>

	       Multiple occurrences in $array1 are all treated the same way. This will output :

	      Array
	      (
		  [1] => blue
	      )

NOTES

       Note

	       Two  elements  are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is
	      the same.

       Note

	       This function only checks  one  dimension  of  a  n-dimensional	array.	Of  course  you  can  check  deeper  dimensions  by  using
	      array_diff($array1[0], $array2[0]);.

SEE ALSO

       array_diff_assoc(3), array_intersect(3), array_intersect_assoc(3).

PHP Documentation Group 													     ARRAY_DIFF(3)
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