added BasicMode.c and refractoring to testForOperator/taschenrechner.h

src/main/c/BasicMode.c

@@ -6,3 +6,51 @@
 #include "taschenrechner.h"
 
 
+void BasicMode() {
+	char endtmp = '0';	//0 false, 1 true
+	double result = 0;
+	double numbers[100] = {0.0};
+	char operatoren[100];
+
+	do {
+		//100 doubles in this array  goes through the for loop till 100 numbers or = is entered
+		for (int i = 0; i < 100) {
+			printf("Enter a Number: ");
+			numbers[i] = testForNumber();	//gets number
+
+			printf("Enter a operation: ");
+			operator[i] = testForOperator();	//gets operator
+
+			if (i > 1) {	//if function to prevent numbers[-1] 
+				switch (operator[i])		//checks of the operator and switches to the case with the needed function
+				{
+				case '+': 
+					result += add(numbers[i - 1], numbers[i])
+					break;
+
+				case '-':
+					result += minus(numbers[i - 1], numbers[i])
+					break;
+
+				case '*':
+					result += multiply(numbers[i - 1], numbers[i])
+					break;
+
+				case '/':
+					result += divide(numbers[i - 1], numbers[i])
+					break;
+
+				case '=':
+					printf("The result is: %d", result);
+					endtmp = 1;
+					break;
+
+				default:
+					break;
+				}
+			}
+			i++;
+		}
+	} while (endtmp != '1')
+
+}

src/main/c/taschenrechner.h

@@ -16,6 +16,9 @@ doulbe divide(doulbe a, doulbe b);
 //get input and check if its a number
 double testForNumber()
 
+//get input and check if its a operator
+char testForOperator()
+
 // Square root function
 double squareRootFunction(double x);
 

src/main/c/testForOperator.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include "taschenrechner.h"
+
+char testForOperator() {
+    //saving the number of operators in a variable so it only needs to be changed in one location
+    int numberOfOperators = 5;
+    //array where all valid Operators are saved, can be esily expanded
+    char oppArray[numberOfOperators] = { '+','-','*','/','=' };
+    char input;
+    bool validInput = false;
+
+    //Loops as long as input isn't valid, enters at least one time
+    while (!validInput) {
+        scanf_s("%c\n", &input);
+        //checks every position of the array if a position is equal to input returns the input, which also stopps the function
+        for (int i = 0; i <= numberOfOperators; i++) {
+            if (input == oppArray[i]) {
+                return input;
+            }
+        }
+        //if the input was deemed invalid it asks for new input and goes to the top of the while loop
+        printf("Diese Eigabe war nicht zulässig probieren sie es noch einmal!\n");
+    }
+}