Login or Register to Ask a Question and Join Our Community

Sponsored Content
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;
}

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Arrays

Dear all, How can i unset arrays. I mean all the subscripts including the array after using them. Could you direct me to some links of array memory handling in the korn shell. Thanks (2 Replies)
Discussion started by: earlysame55
2 Replies

2. Web Development

PHP arrays in arrays

PHP question... I have an SQL query that's pulled back user IDs as a set of columns. Rather than IDs, I want to use their names. So I have an array of columns $col with values 1,7,3,12 etc and I've got an array $person with values "Fred", "Bert", "Tom" etc So what I want to do is display the... (3 Replies)
Discussion started by: JerryHone
3 Replies

3. UNIX for Dummies Questions & Answers

arrays how to?

Hello, I am some what of a newbie to awk scripting and I seem to be struggling with this problem. I know I need to use arrays but I can't figure out how to use them. I have an input file that looks like this; Name,Team,First Test, Second Test, Third Test Crystal,Red,5,17,22... (1 Reply)
Discussion started by: vlopez
1 Replies

4. HP-UX

Hitachi arrays to HP-UX 11.11

We have 2 servers (L1000 and rp7410) running 11.11. We would like to hook them up to either a Hitatchi AMS 2500 or Hitachi USPV via fiber channel. I need to what drivers I need for this and if it will work. Oh, they are using HP Tachyon XL2 Fiber Channel Mass Storage Adapters. Thanks, Bill (1 Reply)
Discussion started by: wsmcelroy
1 Replies

5. Shell Programming and Scripting

2d arrays in unix

hi everybody can anyone help me with usage of 2 dimensional arrays in unix. please provide a suitable example for accessing individual elements as well as all elements. Thanks (2 Replies)
Discussion started by: jpriyank
2 Replies

6. Shell Programming and Scripting

Using arrays in shell

I have three arrays. One is Master array and that has list of other array in config file. for e.g (for simplicity I have only defined array with 2 elements each) set +A MASTERARRAY SQLUPDATE_ONETIME SQLUPDATE_DAILY END_OF_ARRAY set +A SQLUPDATE_ONETIME update12 update22 END_OF_ARRAY... (4 Replies)
Discussion started by: anish
4 Replies

7. Programming

question about int arrays and file pointer arrays

if i declare both but don't input any variables what values will the int array and file pointer array have on default, and if i want to reset any of the elements of both arrays to default, should i just set it to 0 or NULL or what? (1 Reply)
Discussion started by: omega666
1 Replies

8. Shell Programming and Scripting

How can I use the arrays ?

Hi all, I have a file test1.txt with the below contents abc def ghj xyz I tried printing these values using arrays. Script tried : =========== set -A array1 `cat test1.txt` count=${#array1 } i=0 while do echo "element of array $array1" done (1 Reply)
Discussion started by: dnam9917
1 Replies

9. Shell Programming and Scripting

Using arrays?

I have never used arrays before but I have a script like this: var1=$(for i in $(cat /tmp/jobs.021013);do $LIST -job $i -all | perl -ne 'print /.*(\bInfo.bptm\(pid=\d{3,5}).*/' | tr -d "(Info=regpid" | tr -d ')'; $LIST -job $i -all | cut -f7 -d','| sed -e "s/^\(*\)\(*\)\(*\)\(.*\)/\1... (2 Replies)
Discussion started by: newbie2010
2 Replies

10. UNIX for Dummies Questions & Answers

Arrays

Am using bash For eg: Suppose i have a array arr=(1 2 3 4 5 6 7 8 9 10 11 12) suppose i give input 5 to a script and script should able to print values greater than or equal to 5 like below: Input: 5 output: 5,6,7,8,9,10,11,12 (7 Replies)
Discussion started by: manid
7 Replies

LEARN ABOUT REDHAT

raid0run

raid0run(8)						      System Manager's Manual						       raid0run(8)

NAME

       raid0run - starts up old (superblock-less) RAID0/LINEAR arrays

SYNOPSIS

       raid0run [--configfile] [--version] [--force]	       [--upgrade] [-acvfuv] </dev/md?>+

DESCRIPTION

       raid0run  sets up a set of block devices into a single RAID0 array.  It looks in its configuration file for the md devices mentioned on the
       command line, and initializes those arrays.  raid0run only works for RAID0 and LINEAR devices, it's ment as a compatibility/migration  com-
       mand for arrays created with old mdtools.

       Note  that  initializing  RAID devices with the wrong RAID configuration file might destroy all data on the consituent devices! RAID arrays
       with superblocks are much safer and are auto-started by the kernel..

OPTIONS

       -c, --configfile filename
	      Use filename as the configuration file (/etc/raidtab is used by default).

       -a, --all
	      Starts up all nonpersistent RAID0 and LINEAR arrays defined in raidtab.  It skips all persistent or  non-RAID0/LINEAR  arrays.  This
	      switch is handy to be used in startup scripts for old installations.

       -h, --help
	      Displays a short usage message, then exits.

       -V, --version
	      Displays a short version message, then exits.

NOTES

       The  raidtools  are  derived from the md-tools and raidtools packages, which were originally written by Marc Zyngier, Miguel de Icaza, Gadi
       Oxman, Bradley Ward Allen, and Ingo Molnar.

BUGS

       no known bugs.

SEE ALSO

       raidtab(5)

																       raid0run(8)
All times are GMT -4. The time now is 09:42 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy