{"id":212,"date":"2026-03-19T12:23:28","date_gmt":"2026-03-19T12:23:28","guid":{"rendered":"https:\/\/sites.wsagames.com\/jl9u24\/?p=212"},"modified":"2026-03-19T13:05:50","modified_gmt":"2026-03-19T13:05:50","slug":"math-in-c","status":"publish","type":"post","link":"https:\/\/sites.wsagames.com\/jl9u24\/2026\/03\/19\/math-in-c\/","title":{"rendered":"Math in C++"},"content":{"rendered":"\n

Previously I have learned the basics on starting and ending a code including the basic data types.<\/p>\n\n\n\n

Data type<\/td>Size (byte)<\/td>Description<\/td><\/tr>
boolean<\/code><\/td>1<\/td>Stores true or false values<\/td><\/tr>
char<\/code><\/td>1<\/td>Stores a single character\/letter\/number or ASCII values<\/td><\/tr>
int<\/code><\/td>2 or 4<\/td>Stores whole numbers, without decimals<\/td><\/tr>
float<\/code><\/td>4<\/td>Stores fractional number, containing one or more decimals. Sufficient for storing 6-7 decimal digits<\/td><\/tr>
double<\/code><\/td>8<\/td>Stores fractional numbers, containing one or more decimals. Sufficient for storing 15 decimal digits<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Using these I can use it for simple maths.<\/p>\n\n\n\n

By using int when I need to store a whole number without decimals, I can store numbers such as 25, 1000, or even 210981324.<\/p>\n\n\n\n

and float or double for “floating” point numbers like 9.99 or 3.14159265<\/p>\n\n\n\n

int myNum = 1000;\ncout << myNum;<\/code><\/pre>\n\n\n\n
float myNum = 5.5;\ncout << myNum;\n<\/code><\/pre>\n\n\n\n
double myNum = 3.1415;\ncout << myNum;<\/code><\/pre>\n\n\n\n
float<\/code> vs double<\/code><\/p>\n\n\n\n
The precision of a floating point value indicates how many digits the value can have after the decimal point. The precision of float<\/code> is only six or seven decimal digits, while double<\/code> variables have a precision of about 15 digits. Therefore it is safer to use double <\/code>for most calculations.<\/p>\n\n\n\n
A floating point number can also be a scientific number with an “e” to indicate the power of 10<\/p>\n\n\n\n
float f1 = 35e3;\ndouble d1 = 12E4;\ncout << f1;\ncout << d1;<\/code><\/pre>\n\n\n\n
Max and Min<\/h2>\n\n\n\n
The max(x,y)<\/code> function can be used top find the highest value of x and y<\/p>\n\n\n\n
cout << max(5, 10);<\/code><\/pre>\n\n\n\n
and the min(x,y)<\/code> function can be used to find the lowest value of x and y<\/p>\n\n\n\n
cout << min(5, 10);<\/code><\/pre>\n\n\n\n
C++ <cmath> library<\/h2>\n\n\n\n
Other functions such as sqrt (square root), round <\/code>(rounds a number) and log <\/code>(natural logarithm) can be found in the <cmath><\/code> header file.<\/p>\n\n\n\n
\/\/ Include the cmath library\n#include <cmath>\n\ncout << sqrt(64);\ncout << round(2.7);\ncout << log(2);\n<\/code><\/pre>\n\n\n\n
Building a Calculator<\/h2>\n\n\n\n
#include <iostream>   \/\/ For input\/output operations (cin, cout)\n#include <limits>     \/\/ For numeric_limits (handling input errors)\n#include <cmath>      \/\/ For mathematical functions (pow, sqrt, etc.)\n\nusing namespace std;  \/\/ Allows us to use standard library names without std:: prefix\n\n\/\/ Function to display the calculator menu\nvoid displayMenu() {\n    cout << \"\\n=== SIMPLE CALCULATOR ===\\n\";\n    cout << \"1. Addition (+)\\n\";\n    cout << \"2. Subtraction (-)\\n\";\n    cout << \"3. Multiplication (*)\\n\";\n    cout << \"4. Division (\/)\\n\";\n    cout << \"5. Power (^)\\n\";\n    cout << \"6. Square Root (\u221a)\\n\";\n    cout << \"7. Exit\\n\";\n    cout << \"Enter your choice (1-7): \";\n}\n\n\/\/ Function to get a valid number from user\ndouble getNumber(string prompt) {\n    double num;\n    while (true) {\n        cout << prompt;\n        cin >> num;\n        \n        \/\/ Check if input failed (user entered non-numeric)\n        if (cin.fail()) {\n            cin.clear(); \/\/ Clear error flag\n            cin.ignore(numeric_limits<streamsize>::max(), '\\n'); \/\/ Discard invalid input\n            cout << \"Invalid input! Please enter a number.\\n\";\n        } else {\n            cin.ignore(numeric_limits<streamsize>::max(), '\\n'); \/\/ Clear input buffer\n            return num;\n        }\n    }\n}\n\n\/\/ Function to perform addition\ndouble add(double a, double b) {\n    return a + b;  \/\/ Simply return sum\n}\n\n\/\/ Function to perform subtraction\ndouble subtract(double a, double b) {\n    return a - b;  \/\/ Simply return difference\n}\n\n\/\/ Function to perform multiplication\ndouble multiply(double a, double b) {\n    return a * b;  \/\/ Simply return product\n}\n\n\/\/ Function to perform division with error checking\ndouble divide(double a, double b) {\n    if (b == 0) {  \/\/ Check for division by zero\n        cout << \"Error: Division by zero is not allowed!\\n\";\n        return 0;  \/\/ Return 0 as default value\n    }\n    return a \/ b;  \/\/ Return quotient\n}\n\n\/\/ Function to calculate power\ndouble power(double base, double exponent) {\n    return pow(base, exponent);  \/\/ Use cmath's pow function\n}\n\n\/\/ Function to calculate square root with error checking\ndouble squareRoot(double num) {\n    if (num < 0) {  \/\/ Check for negative numbers\n        cout << \"Error: Cannot calculate square root of negative number!\\n\";\n        return 0;  \/\/ Return 0 as default value\n    }\n    return sqrt(num);  \/\/ Use cmath's sqrt function\n}\n\nint main() {\n    int choice;           \/\/ Variable to store user's menu choice\n    double num1, num2;    \/\/ Variables to store operands\n    double result;        \/\/ Variable to store calculation result\n    \n    cout << \"Welcome to the C++ Calculator!\\n\";\n    \n    \/\/ Main program loop - continues until user chooses to exit\n    while (true) {\n        displayMenu();  \/\/ Show menu options\n        cin >> choice;  \/\/ Get user's choice\n        \n        \/\/ Check if menu input is valid\n        if (cin.fail()) {\n            cin.clear();\n            cin.ignore(numeric_limits<streamsize>::max(), '\\n');\n            cout << \"Invalid choice! Please enter a number.\\n\";\n            continue;  \/\/ Skip rest of loop and start over\n        }\n        \n        \/\/ Handle exit option\n        if (choice == 7) {\n            cout << \"Thank you for using the calculator. Goodbye!\\n\";\n            break;  \/\/ Exit the while loop, ending the program\n        }\n        \n        \/\/ Process calculator operations based on user's choice\n        switch(choice) {\n            case 1:  \/\/ Addition\n                cout << \"\\n--- ADDITION ---\\n\";\n                num1 = getNumber(\"Enter first number: \");\n                num2 = getNumber(\"Enter second number: \");\n                result = add(num1, num2);\n                cout << num1 << \" + \" << num2 << \" = \" << result << \"\\n\";\n                break;\n                \n            case 2:  \/\/ Subtraction\n                cout << \"\\n--- SUBTRACTION ---\\n\";\n                num1 = getNumber(\"Enter first number: \");\n                num2 = getNumber(\"Enter second number: \");\n                result = subtract(num1, num2);\n                cout << num1 << \" - \" << num2 << \" = \" << result << \"\\n\";\n                break;\n                \n            case 3:  \/\/ Multiplication\n                cout << \"\\n--- MULTIPLICATION ---\\n\";\n                num1 = getNumber(\"Enter first number: \");\n                num2 = getNumber(\"Enter second number: \");\n                result = multiply(num1, num2);\n                cout << num1 << \" * \" << num2 << \" = \" << result << \"\\n\";\n                break;\n                \n            case 4:  \/\/ Division\n                cout << \"\\n--- DIVISION ---\\n\";\n                num1 = getNumber(\"Enter dividend: \");\n                num2 = getNumber(\"Enter divisor: \");\n                result = divide(num1, num2);\n                if (num2 != 0) {  \/\/ Only display result if division was valid\n                    cout << num1 << \" \/ \" << num2 << \" = \" << result << \"\\n\";\n                }\n                break;\n                \n            case 5:  \/\/ Power\n                cout << \"\\n--- POWER ---\\n\";\n                num1 = getNumber(\"Enter base: \");\n                num2 = getNumber(\"Enter exponent: \");\n                result = power(num1, num2);\n                cout << num1 << \" ^ \" << num2 << \" = \" << result << \"\\n\";\n                break;\n                \n            case 6:  \/\/ Square Root\n                cout << \"\\n--- SQUARE ROOT ---\\n\";\n                num1 = getNumber(\"Enter number: \");\n                result = squareRoot(num1);\n                if (num1 >= 0) {  \/\/ Only display result if input was valid\n                    cout << \"\u221a\" << num1 << \" = \" << result << \"\\n\";\n                }\n                break;\n                \n            default:  \/\/ Invalid menu choice\n                cout << \"Invalid choice. Please select 1-7.\\n\";\n        }\n        \n        cout << \"\\nPress Enter to continue...\";\n        cin.get();  \/\/ Wait for user to press Enter\n    }\n    \n    return 0;  \/\/ Program ended successfully\n}<\/code><\/pre>\n\n\n\n
Detailed Explanation<\/h2>\n\n\n\n
Header Files (Lines 1-3)<\/strong><\/h3>\n\n\n\n