How To Get Size Of Array C

Become the Size of Array in C

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

sizeof() Operator to Make up one's mind 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 Determine the Size of an Assortment 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 measurement of byte.

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

The output may be different on different machines like a 32-flake system tin show unlike output and a 64-bit arrangement can show different of the aforementioned 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, bladder equally a primitive data type.

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

Output:

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

Get Length of Array in C

If we divide the assortment's total size by the size of the array element, we get the number of elements in the assortment. The plan is equally below:

              #include<stdio.h>  int principal(void)  {     int number[xvi];          size_t due north = sizeof(number)/sizeof(number[0]);     printf("Full elements the array tin concur is: %d\n",n);          return 0; }

Output:

              Full elements the array can hold is: xvi

When an array is passed every bit a parameter to the function, information technology treats as a pointer. The sizeof() operator returns the arrow size instead of array size. So inside functions, this method won't piece of work. Instead, pass an boosted parameter size_t size to point the number of elements in the array.

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

              sizeof of the assortment is: 28 sizeof of the parameter is: eight Length of the assortment 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: seven Length of the parameter is: ane

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