les 1

les-1/main.js

@@ -103,7 +103,7 @@ const askName = function() {
         alert ('Jij bent niet de leraar');
     }
 }
-askName(); */
+askName(); 
 
 Number.isNaN(NaN);
 console.log(Number.isNaN(5));
@@ -115,4 +115,37 @@ const sumNumber = function() {
 
     alert(firstNumber + secondNumber);
 }
-sumNumber();
+sumNumber();
+
+function getPrimes(max) {
+    var sieve = [], i, j, primes = [];
+    for (i = 2; i <= max; ++i) {
+        if (!sieve[i]) {
+            // i has not been marked -- it is prime
+            primes.push(i);
+            for (j = i << 1; j <= max; j += i) {
+                sieve[j] = true;
+            }
+        }
+    }*/
+    return primes;
+}
+console.log(getPrimes());
+
+const askNumber = function (firstNumber,secondNumber){ // function to ask 2 numbers.
+    while (isNaN(firstNumber)||isNaN(secondNumber)){
+    firstNumber = parseInt(prompt ('First number?'));
+    secondNumber = parseInt(prompt ('Second number?'));  
+        if(firstNumber != NaN && secondNumber != NaN){ // 2 numbers must not be NaN
+        alert(firstNumber + secondNumber);
+         }
+     }
+}
+console.log(askNumber());
+
+let firstNumber = parseInt(prompt ('First number?'));
+while (isNaN(numberOne){
+    secondNumber = parseInt(prompt ('Second number?'));  
+}
+while (isNaN(numberTwo)){
+}