finally finished lab

index.js

@@ -4,7 +4,44 @@
  * Depending on the operation, either add up all of the numbers or subtract all of the numbers, from left to right.
  * @returns {number} The result of either adding all numbers or subtracting all numbers, depending on the arguments added to the command line.
  */
-function calculator() {}
-
+//function calculator() {
+//     let argvs = process.argv.slice(2)
+//     if (argvs < 1 ){
+//         return "No operation provided..."
+//     }   else if (argvs[0] === "plus" || argvs[0] === "minus" && )
+
+//     if (argvs[0] === "plus"){
+//         return a + b
+//     }   else if (argvs[0] === "minus"){
+//         return a - b
+//     }
+//     return a + b; 
+// }
+function calculator() {
+   if (!process.argv[2]) {
+      return "No operation provided...";
+}      if (!process.argv[3]){
+      return "No numbers provided...";
+     } if (process.argv[2] === "plus") {
+      let newArg = process.argv.slice(3);
+      let sum = 0;
+      sum = newArg.reduce((accumulator, value) => {
+     return accumulator + +value}, 0);
+     return sum;
+  }  if( process.argv[2] === 'minus'){
+    let newArg = process.argv.slice(3); 
+    let result = newArg[0]
+    for(let i = 1; i < newArg.length; i++){
+    result -= Number(newArg[i])
+}
+    return result
+  } if (process.argv[2] !== "plus" || process.argv[2] !== "minus") {
+            return "Invalid operation: modulo"
+} 
+}
+// const commandPlus = "plus";
+// const commandMinus = "minus";
+// const numbers = ["5", "10"];
+// process.argv.push(command, ...numbers);
 // Don't change anything below this line.
 module.exports = calculator;