5 files changed, 223 insertions, 0 deletions
diff --git a/src/Calculator.java b/src/Calculator.java
new file mode 100644
index 0000000..6f2cb94
--- /dev/null
+++ b/src/Calculator.java
@@ -0,0 +1,53 @@
+import java.util.Scanner;
+
+class InvalidOperatorException extends Exception {
+	public InvalidOperatorException(String errorMessage) {
+		super(errorMessage);
+	}
+}
+
+public class Calculator {
+	private static float calculate(String operator, float number1, float number2) throws InvalidOperatorException {
+		switch(operator) {
+			case "+":
+				return number1 + number2;
+			case "-":
+				return number1 - number2;
+			case "/":
+				return number1 / number2;
+			case "*":
+				return number1 * number2;
+			default:
+				throw new InvalidOperatorException("invalid operator used!");
+		}
+	}
+
+	public static void main(String[] args) {
+		Scanner scan = new Scanner(System.in);
+
+		float number1, number2, result;
+		String operator;
+
+		try {
+			System.out.print("enter a number: " );
+			number1 = scan.nextFloat();
+			System.out.print("enter an operator: ");
+			scan.nextLine();
+			operator = scan.nextLine();
+			System.out.print("enter another number: ");
+			number2 = scan.nextFloat();
+		} catch (Exception e) {
+			System.out.println("couldn't get your input!");
+			return;
+		}
+
+		try {
+			result = calculate(operator, number1, number2);
+		} catch (InvalidOperatorException e) {
+			System.out.println(e.getMessage());
+			return;
+		}
+
+		System.out.println(result);
+	}
+}
diff --git a/src/calculator.d b/src/calculator.d
new file mode 100644
index 0000000..c7933be
--- /dev/null
+++ b/src/calculator.d
@@ -0,0 +1,49 @@
+import std.stdio;
+import std.string;
+
+class InvalidOperatorException : Exception {
+	this(string msg, string file = __FILE__, size_t line = __LINE__) {
+		super(msg, file, line);
+	}
+}
+
+float calculate(char[] operator, float number1, float number2) {
+	foreach (c; operator) {
+		switch(c) {
+				case '+':
+					return number1 + number2;
+				case '-':
+					return number1 - number2;
+				case '/':
+					return number1 / number2;
+				case '*':
+					return number1 * number2;
+				default:
+					continue;
+		}
+	}
+	throw new InvalidOperatorException("invalid operator used!");
+}
+
+void main() {
+	char[] operator;
+	float number1;
+	float number2;
+	write("enter a number: ");
+	readf("%f", &number1);
+
+	write("enter an operator: ");
+	readf(" %s\n", &operator);
+
+	write("enter another number: ");
+  readf(" %f", &number2);
+
+	float result;
+	try {
+		result = calculate(operator, number1, number2);
+	} catch (InvalidOperatorException e) {
+		writeln(e);
+	}
+
+	writeln(result);
+}
diff --git a/src/calculator.hs b/src/calculator.hs
new file mode 100644
index 0000000..1da13af
--- /dev/null
+++ b/src/calculator.hs
@@ -0,0 +1,22 @@
+calculate :: String -> Float -> Float -> Float
+calculate operator number1 number2 = case operator of
+  "+" -> number1 + number2
+  "-" -> number1 - number2
+  "/" -> number1 / number2
+  "*" -> number1 * number2
+  _ -> error "invalid operator!"
+
+main :: IO()
+main = do
+  putStr "enter a number: "
+  input<-getLine
+  let number1 = (read input :: Float)
+
+  putStr "enter an operator: "
+  operator<-getLine
+
+  putStr "enter another number: "
+  input<-getLine
+  let number2 = (read input :: Float)
+
+  print (calculate operator number1 number2)
diff --git a/src/calculator.rs b/src/calculator.rs
new file mode 100644
index 0000000..eab3ac8
--- /dev/null
+++ b/src/calculator.rs
@@ -0,0 +1,58 @@
+use std::error::Error;
+use std::fmt;
+use std::io;
+use std::process;
+
+#[derive(Debug)]
+struct UnknownOperatorError;
+
+impl Error for UnknownOperatorError {}
+
+impl fmt::Display for UnknownOperatorError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "invalid operator!")
+    }
+}
+
+fn get_input() -> String {
+    let mut res = String::new();
+    io::stdin()
+        .read_line(&mut res)
+        .expect("failed to get input!");
+
+    return (*res).trim().to_string();
+}
+
+fn get_number() -> f32 {
+    get_input()
+        .parse::<f32>()
+        .expect("failed to get your number (possible lack of rizz)")
+}
+
+fn calculate(operator: &String, number1: &f32, number2: &f32) -> Result<f32, UnknownOperatorError> {
+    match operator.as_str() {
+        "+" => Ok(number1 + number2),
+        "-" => Ok(number1 - number2),
+        "/" => Ok(number1 / number2),
+        "*" => Ok(number1 * number2),
+        _ => Err(UnknownOperatorError),
+    }
+}
+
+fn main() {
+    println!("enter a number: ");
+    let number1 = get_number();
+    println!("enter an operator: ");
+    let operator = get_input();
+    println!("enter another number: ");
+    let number2 = get_number();
+
+    let res = calculate(&operator, &number1, &number2);
+    match res {
+        Ok(i) => println!("{i}"),
+        Err(e) => {
+            eprintln!("{e}");
+            process::exit(1);
+        }
+    }
+}
diff --git a/src/calculator.swift b/src/calculator.swift
new file mode 100644
index 0000000..dfd4c4c
--- /dev/null
+++ b/src/calculator.swift
@@ -0,0 +1,41 @@
+enum InvalidOperatorError: Error {
+    case operatorNotSupported
+}
+
+func calculate(operatorThing: String, number1: Float, number2: Float) throws -> Float {
+    switch operatorThing {
+    case "+":
+        return number1 + number2
+    case "-":
+        return number1 - number2
+    case "/":
+        return number1 / number2
+    case "*":
+        return number1 * number2
+    default:
+       throw InvalidOperatorError.operatorNotSupported
+    }
+}
+
+
+func main() {
+    print("enter a number:")
+    let number1 = Float(readLine()!)!
+    print("enter an operator:")
+    let operatorThing = readLine()!
+    print("enter another number:")
+    let number2 = Float(readLine()!)!
+    
+    do {
+        let result = try calculate(operatorThing: operatorThing, number1: number1, number2: number2) 
+        print(result)
+    } catch InvalidOperatorError.operatorNotSupported {
+        print("invalid operator!")
+        return
+    } catch {
+        print("unexpected error!")
+        return
+    }
+}
+
+main()