How To Find The Size Of An Array In C++

Get the Size of Array in C

Created: November-x, 2020 | Updated: Dec-x, 2020

sizeof() Operator to Determine the Size of an Array in C
Get Length of Array in C

This tutorial introduces how to determine the length of an array in C. The sizeof() operator is used to get the size/length of an array.

`sizeof()` Operator to Decide the Size of an Array in C

The sizeof() operator is a compile-time unary operator. Information technology is used to calculate the size of its operand. It returns the size of a variable. The sizeof() operator gives the size in the unit of byte.

The sizeof() operator is used for whatsoever data type such as primitives like int, float, char, and also non-primitives data type as an array, struct. It returns the memory allocated to that information type.

The output may exist different on dissimilar machines like a 32-bit system tin show different output and a 64-bit system can show dissimilar of the same information types.

Syntax of `sizeof()`:

              sizeof(operand)

The operand is a data-type or any operand.

`sizeof()` Operator for Primitive Data Types in C

This program uses an int, float as a archaic data type.

              #include <stdio.h>   int master(void)  {      printf("Size of char information blazon: %u\north",sizeof(char));      printf("Size of int data blazon: %u\north",sizeof(int));      printf("Size of float data type: %u\n",sizeof(float));      printf("Size of double data type: %u\due north",sizeof(double));           return 0;  }

Output:

              Size of char data type: 1 Size of int information type: iv Size of float information type: iv Size of double information type: eight

Get Length of Array in C

If we carve up the array's total size by the size of the assortment element, we get the number of elements in the array. The program is as below:

              #include<stdio.h>  int main(void)  {     int number[16];          size_t northward = sizeof(number)/sizeof(number[0]);     printf("Total elements the assortment tin can concur is: %d\n",north);          return 0; }

Output:

              Total elements the array can hold is: 16

When an assortment is passed every bit a parameter to the function, it treats as a arrow. The sizeof() operator returns the arrow size instead of assortment size. Then within functions, this method won't piece of work. Instead, pass an additional parameter size_t size to indicate the number of elements in the assortment.

              #include<stdio.h> #include<stdlib.h>  void printSizeOfIntArray(int intArray[]); void printLengthIntArray(int intArray[]);  int main(int argc, char* argv[]) {     int integerArray[] = { 0, 1, 2, 3, 4, 5, 6 };      printf("sizeof of the array is: %d\northward", (int) sizeof(integerArray));     printSizeOfIntArray(integerArray);          printf("Length of the assortment is: %d\due north", (int)( sizeof(integerArray) / sizeof(integerArray[0]) ));     printLengthIntArray(integerArray);  }  void printSizeOfIntArray(int intArray[]) {     printf("sizeof of the parameter is: %d\due north", (int) sizeof(intArray)); }  void printLengthIntArray(int intArray[]) {     printf("Length of the parameter is: %d\north", (int)( sizeof(intArray) / sizeof(intArray[0]) )); }

Output (in a 64-scrap Linux Bone):

              sizeof of the array is: 28 sizeof of the parameter is: 8 Length of the array is: 7 Length of the parameter is: 2

Output (in a 32-bit Windows OS):

              sizeof of the array is: 28 sizeof of the parameter is: 4 Length of the array is: vii Length of the parameter is: 1

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