Function Pointer Calculator
Medium
C
Functions
34 views
Problem Statement
Create char array of functions: add, subtract, multiply, divide. Take operator input from the user and call the corresponding function pointer. Dynamic function selection demo.
Input Format
Two numbers and an operator character (+, -, *, /).
Output Format
Result of the selected operation.
Example
Number 1: 10 Number 2: 5 Operator: *
Result = 50
Constraints
• Valid operators: +, -, *, /
• Division by zero must be handled
• Division by zero must be handled
Concept Explanation
The program selects and calls a function dynamically using a function pointer based on the operator entered by the user.
Step-by-Step Explanation
1.Create four separate functions:
• add
• subtract
• multiply
• divide
2.Create an array of function pointers, where each pointer points to one operation function.
3.Create a corresponding array of operator characters (+, -, *, /).
4.Take two numbers as input from the user.
5.Take an operator character as input.
6.Traverse the operator array to find a match with the user input.
7.When a match is found:
• Use the same index to access the function pointer array.
• Call the function through the function pointer.
8.If the operator is division and the second number is zero:
• Show an error message.
9.If no matching operator is found:
• Show an invalid operator error.
• add
• subtract
• multiply
• divide
2.Create an array of function pointers, where each pointer points to one operation function.
3.Create a corresponding array of operator characters (+, -, *, /).
4.Take two numbers as input from the user.
5.Take an operator character as input.
6.Traverse the operator array to find a match with the user input.
7.When a match is found:
• Use the same index to access the function pointer array.
• Call the function through the function pointer.
8.If the operator is division and the second number is zero:
• Show an error message.
9.If no matching operator is found:
• Show an invalid operator error.
Concept Explanation
The program selects and calls a function dynamically using a function pointer based on the operator entered by the user.
Step-by-Step Explanation
1.Create four separate functions:
• add
• subtract
• multiply
• divide
2.Create an array of function pointers, where each pointer points to one operation function.
3.Create a corresponding array of operator characters (+, -, *, /).
4.Take two numbers as input from the user.
5.Take an operator character as input.
6.Traverse the operator array to find a match with the user input.
7.When a match is found:
• Use the same index to access the function pointer array.
• Call the function through the function pointer.
8.If the operator is division and the second number is zero:
• Show an error message.
9.If no matching operator is found:
• Show an invalid operator error.
• add
• subtract
• multiply
• divide
2.Create an array of function pointers, where each pointer points to one operation function.
3.Create a corresponding array of operator characters (+, -, *, /).
4.Take two numbers as input from the user.
5.Take an operator character as input.
6.Traverse the operator array to find a match with the user input.
7.When a match is found:
• Use the same index to access the function pointer array.
• Call the function through the function pointer.
8.If the operator is division and the second number is zero:
• Show an error message.
9.If no matching operator is found:
• Show an invalid operator error.
Input / Output Format
Input Format
Two numbers and an operator character (+, -, *, /).
Output Format
Result of the selected operation.
Constraints
• Valid operators: +, -, *, /
• Division by zero must be handled
• Division by zero must be handled
Examples
Input:
Number 1: 10
Number 2: 5
Operator: *
Output:
Result = 50
Example Solution (Public)
#include <stdio.h>
/* Function prototypes */
int add(int a, int b) { return a + b; }
int subtract(int a, int b) { return a - b; }
int multiply(int a, int b) { return a * b; }
int divide(int a, int b) {
if (b == 0) {
printf("Error: Division by zero!n");
return 0;
}
return a / b;
}
int main() {
char op;
int x, y;
/* Array of function pointers */
int (*funcPtr[4])(int, int) = {add, subtract, multiply, divide};
char operators[4] = {'+', '-', '*', '/'};
printf("Enter two numbers: ");
scanf("%d %d", &x, &y);
printf("Enter operator (+, -, *, /): ");
scanf(" %c", &op);
int i, found = 0;
for (i = 0; i < 4; i++) {
if (op == operators[i]) {
int result = funcPtr[i](x, y); // Call corresponding function
printf("Result: %d %c %d = %dn", x, op, y, result);
found = 1;
break;
}
}
if (!found) {
printf("Error: Invalid operator!n");
}
return 0;
}
Official Solution Code
#include <stdio.h>
/* Function prototypes */
int add(int a, int b) { return a + b; }
int subtract(int a, int b) { return a - b; }
int multiply(int a, int b) { return a * b; }
int divide(int a, int b) {
if (b == 0) {
printf("Error: Division by zero!n");
return 0;
}
return a / b;
}
int main() {
char op;
int x, y;
/* Array of function pointers */
int (*funcPtr[4])(int, int) = {add, subtract, multiply, divide};
char operators[4] = {'+', '-', '*', '/'};
printf("Enter two numbers: ");
scanf("%d %d", &x, &y);
printf("Enter operator (+, -, *, /): ");
scanf(" %c", &op);
int i, found = 0;
for (i = 0; i < 4; i++) {
if (op == operators[i]) {
int result = funcPtr[i](x, y); // Call corresponding function
printf("Result: %d %c %d = %dn", x, op, y, result);
found = 1;
break;
}
}
if (!found) {
printf("Error: Invalid operator!n");
}
return 0;
}
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