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04 Arrays

linear data structure

primitive data structure

arrays are 0-indexed

  • index start from 0

it is non-mutable (non-changeable)

statically-allocated

size of array is fixed

array is similar to tuple in python, but only same data type

collection of elements of the same data type

\(\ne\) List

In python, list is a collection of elements of the same/different type

list = [2, "hi", 3, 4, 5]

Declaration/Creation

int array[10];

char array[10];
float array[10];
double array[10];
const int length = 10;
int array[length];

Initialization

array[0]= 1;
array[1] = 2;

int num;
scanf("%d", &num);
array[2] = num;
scanf("%d", &num);
array[3] = num;

for(int i=0; i<10; i++)
{
  int num;
  scanf("%d", &num);
  array[i] = num;
}

// no error

for(int i=0; i<10; i++)
{
  scanf("%d", array[i]); // no &
}

// no error

for(int i=1; i<=9; i++)
{
  scanf("%d", &num);
  array[i] = num;
}

// no error

Display

for(int i=0; i<10; i++)
{
  printf("%d\n", array[i]);
}

example

#include <iostream.h>

int main()
{
  int a[100]; // assuming a random number


  // input no of elements
  int n;
  printf("Please enter no of elements that you are goint to input");
  scanf("%d", &n);

  // input the elements
  for(int i=0; i<n; i++)
  {
    printf("Enter number at index %d: ", i);
    scanf("%d", a[i]);
  }

  // display marks > 60
  for(int i=0; i<n; i++)
  {
    if(a[i] > 60)
      printf("%d", a[i]);
  }
  // or
  for(int i=0; i<n; i++)
  {
    int num = a[i];
    if(num > 60)
      printf("%d", num);
  }

  return 0;
}
Last Updated: 2023-01-25 ; Contributors: AhmedThahir

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