• 0

Dynamic Array in C++ (Please help me I don't understand some code line, somebody please explain them for me)


Question

This is a function to insert A Number at A Position in a dynamic array ;

1/ I don't understand from the line "moveCount". What is moveCount for , and, Why move count = size - index;

2/ what in the function "memmove" in c++

3/ could you please explain the codes from the line "ARROW" to the end ?

Thank you so much for helping me ( I am just a stupid child trying to mess around with code :) )

Untitled.png

Edited by crop_duster

1 answer to this question

Recommended Posts

  • 0

The moveCount var is basically getting the size of the array minus the index of where you want to insert the new value within the array (the function name is DynamicArray::insertAt after all), the if statement makes sure it is an array and if, it's not using memmove to increase the size allocated.

 

http://www.cplusplus.com/reference/cstring/memmove/

 

  Quote

memmove

void * memmove ( void * destination, const void * source, size_t num );

Move block of memory

Copies the values of num bytes from the location pointed by source to the memory block pointed by destination. Copying takes place as if an intermediate buffer were used, allowing the destination and source to overlap.

The underlying type of the objects pointed by both the source and destination pointers are irrelevant for this function; The result is a binary copy of the data.

The function does not check for any terminating null character in source - it always copies exactly num bytes.

To avoid overflows, the size of the arrays pointed by both the destination and source parameters, shall be at least numbytes.

 

Parameters

destination

Pointer to the destination array where the content is to be copied, type-casted to a pointer of type void*.

source

Pointer to the source of data to be copied, type-casted to a pointer of type const void*.

num

Number of bytes to copy.
size_t is an unsigned integral type.

Expand  

 

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Samsung could unveil its Galaxy XR headset ‘Project Moohan' in September by Sagar Naresh Bhavsar Next month, Samsung is expected to unveil the Galaxy Z Fold7, the Galaxy Z Flip7, and an affordable Galaxy Z Flip7 FE, along with the Galaxy Watch8 series. However, the launches don't end there. A fresh report out of South Korea hints that Samsung could launch its much-awaited Galaxy XR augmented reality headset in September. The company has codenamed its first XR headset as "Project Moohan," which translates to "Project Infinite." Samsung has already showcased the Galaxy XR headset a few times in the past. In fact, popular tech YouTuber Marques Brownlee - also known as MKBHD -, got his hands on the Galaxy XR and revealed interesting details about the upcoming device. The Galaxy XR is rumored to come with a sharper display compared to the Apple Vision Pro and run on Google's new operating system for AR and VR headsets, the Android XR. Fast forward to now, Korean publication Newspim reports that Samsung is ready to launch the Galaxy XR headset on September 29 in its home country. Notably, the headset will be unveiled at an Unpacked event and later will go on sale on October 13. Globally, the Galaxy XR headset is expected to launch soon afterwards, though any specific date isn't mentioned. Additionally, the report suggests that fans can expect more teaser videos and prototypes of the headset at the upcoming Unpacked event for the Galaxy Z Fold7 and Flip7. The report also spills some details about the specifications of the Galaxy XR headset. Under the hood, it could run on Qualcomm's new XR2+ Gen 2 chip, made using Samsung's 4nm process. Samsung is also expected to introduce tight integration with its Galaxy ecosystem to offer a connected experience. It will be interesting to see how Samsung holds up against the likes of Meta, which already dominates the XR market, while Apple struggles with high Vision Pro prices.
    • I've put it behind a login for the time being.  I had something like 600,000 requests from just from Alibaba IP addresses that didn't clarify they were bots or scrapers, and so not easy to block using user agent filtering.  I didn't have any issues with bandwidth or accessibility, but that's 600,000 requests just from one cloud provider made to my spinning rust hard drives, that I have to personally pay for when they die, by bots being ran by corrupt mega corporations ignoring my polite requests that they not scrape me and that the information only be accessed by real humans. If any of y'all here were actually using my Kiwix mirror, I have no issue whatsoever creating a username and password for you, just hit me up using one of the methods listed on my personal site and I'll make one for you. https://marcusadams.me
    • I always turn encryption off 1st boot, crazy its on by default on new computers, it should ASK you ON or OFF on 1st boot,, So many people dont even know its on , then forget their windows login and microsoft account,, RETarDED Microsoft is now, , i also find having it on slows things down too
    • Adding AI is just an excuse to hike prices. I don't want any AI features in our Slack workspace and yet will have to pay for it.
    • Hello Could you be kind too help me fix this 3.1gig and not 256gig it says 3.1gig only .someone told me to fix it with this https://www.disk-partition.com/articles/64gb-flash-drive-only-showing-32gb-5740i.html yes my sandisk ultra usb 3.0 256gb wont show up in full .  but i don't know want options i have to use on there can someone  please guide me with step by step instructions please  guide me with step by step instructions on how to repair this .sorry for asking but I've tried but i don't know want i have to do on that programme please help me i am on windows 11 home thank you nick
  • Recent Achievements

    • Week One Done
      vivetool earned a badge
      Week One Done
    • Reacting Well
      pnajbar earned a badge
      Reacting Well
    • Week One Done
      TBithoney earned a badge
      Week One Done
    • First Post
      xuxlix earned a badge
      First Post
    • First Post
      Tomek Święcicki earned a badge
      First Post
  • Popular Contributors

    1. 1
      +primortal
      675
    2. 2
      ATLien_0
      288
    3. 3
      Michael Scrip
      223
    4. 4
      +FloatingFatMan
      195
    5. 5
      Steven P.
      144
  • Tell a friend

    Love Neowin? Tell a friend!