C Exercises: Convert a decimal number to hexadecimal

C For Loop: Exercise-55 with Solution

Write a C program to convert a decimal number to hexadecimal.

Visual Presentation:

Sample Solution:

C Code:

#include <stdio.h>
int main() {
    // Declare variables
    long int decn, q, m;
    int tmp;
    // Print output header
    printf("\n\nConvert Decimal to Hexadecimal:\n ");
    printf("-------------------------\n");
    // Get decimal input
    printf("Input any Decimal number: ");
    scanf("%ld", &decn);
    // Convert decimal to hex
    // Use an array to store hex digits
    char hexDigits[20];  // Adjust the size as needed
    int index = 0;  // Index to store hex digits in the array
    while (decn > 0) {
        // Get remainder
        tmp = decn % 16;
        // Convert to hex digit
        if (tmp < 10) {
            hexDigits[index] = tmp + '0';
        } else {
            hexDigits[index] = tmp + 'A' - 10;
        }
        index++;
        decn = decn / 16;
    }
    // Print hex number in reverse order
    printf("\nThe equivalent Hexadecimal Number : ");
    for (int i = index - 1; i >= 0; i--) {
        printf("%c", hexDigits[i]);
    }
    printf("\n\n");
    return 0;
}

Sample Output:

Convert Decimal to Hexadecimal:                                                                               
 -------------------------                                                                                    
Input  any Decimal number: 79                                                                                 
                                                                                                              
The equivalent Hexadecimal Number : 4F 

Explanation:

Here's a brief explanation.

• Header and Declaration:
• Includes the necessary header file (stdio.h).
• Declare variables 'decn' (decimal input), 'q' (temporary variable), 'm' (temporary variable), and 'tmp' (temporary variable for remainder).
• Declares an array 'hexDigits' to store the hexadecimal digits.
• User Input:
• Asks the user to input a decimal number.
• Reads the input and stores it in the variable 'decn'.
• Conversion Loop:
• Enters a while loop that continues until the decimal number ('decn') becomes zero.
• Inside the loop, calculate the remainder when dividing 'decn' by 16 ('tmp').
• Converts the remainder to a hexadecimal digit and stores it in the 'hexDigits' array.
• Update the 'decn' by dividing it by 16.
• Print Hexadecimal Result:
• Prints the header for hexadecimal output.
• Prints the equivalent hexadecimal number by iterating through the 'hexDigits' array in reverse order.
• Return Statement:
• Returns 0 to indicate successful execution.

Flowchart:

C Programming Code Editor:

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