Update Extract Int from string

Extract Int from string

@@ -48,4 +48,32 @@ int my_getnbr(char *str){           //function declared
 }
 
 
+/* A while loop to calculate string length is useless, so i implemented the algorith right in the while loop */ 
+
+int my_getnbr(char *str){
+    int start_index = 0, int result=0, int multiplier=1, int end_index=0, int i =0;
+    while(str[i] != '\0'){                                      // map where the digits are in the string
+        i++;
+         if (str[i] >= 48 && str[i] <= 57){
+          start_index = i;
+          end_index = start_index;
+          while(str[end_index] >= 48 && str[end_index] <= 57){
+             ++end_index;
+          }
+          end_index = end_index-1;
+          break;
+        }
+    }
+
+    for(int k = end_index; k >= start_index; k--){              // calculate the int
+        result = result + (str[k]-'0')*multiplier;
+        multiplier=multiplier*10;
+    }
+
+    if(str[start_index-1] == 45){                               // if it's negative => *-1
+        result = result * (-1);
+    }
+    return result;
+}
+