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

Get the Size of Assortment in C

Created: November-10, 2020 | Updated: December-10, 2020

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

This tutorial introduces how to make up one's mind the length of an array in C. The sizeof() operator is used to go 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 any data blazon such as primitives like int, float, char, and likewise non-primitives data type equally an array, struct. It returns the retentivity allocated to that data type.

The output may be dissimilar on different machines similar a 32-chip arrangement can show different output and a 64-bit arrangement tin can show unlike of the same data types.

Syntax of `sizeof()`:

              sizeof(operand)

The operand is a data-type or whatever operand.

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

This program uses an int, bladder as a primitive information type.

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

Output:

              Size of char data type: 1 Size of int data type: 4 Size of float data type: iv Size of double data type: 8

Get Length of Array in C

If nosotros divide the assortment's total size by the size of the array element, nosotros get the number of elements in the array. The program is as beneath:

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

Output:

              Total elements the assortment can hold is: 16

When an array is passed equally a parameter to the function, it treats as a pointer. The sizeof() operator returns the pointer size instead of array size. So within functions, this method won't piece of work. Instead, pass an additional parameter size_t size to point 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, ii, iii, four, 5, 6 };      printf("sizeof of the array is: %d\northward", (int) sizeof(integerArray));     printSizeOfIntArray(integerArray);          printf("Length of the assortment is: %d\n", (int)( sizeof(integerArray) / sizeof(integerArray[0]) ));     printLengthIntArray(integerArray);  }  void printSizeOfIntArray(int intArray[]) {     printf("sizeof of the parameter is: %d\n", (int) sizeof(intArray)); }  void printLengthIntArray(int intArray[]) {     printf("Length of the parameter is: %d\northward", (int)( sizeof(intArray) / sizeof(intArray[0]) )); }

Output (in a 64-fleck Linux Os):

              sizeof of the array is: 28 sizeof of the parameter is: eight Length of the array is: seven Length of the parameter is: 2

Output (in a 32-bit Windows OS):

              sizeof of the assortment is: 28 sizeof of the parameter is: 4 Length of the array is: seven Length of the parameter is: 1

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