end of day 4 week 1

week 1/day 4/exo4.ps1

@@ -0,0 +1,24 @@
+$users = @("admin", "root1", "John_Doe", "Alice", "Bob42")
+
+foreach($username in $users){
+
+    $badChar = $false
+
+    foreach($char in $username.ToCharArray()){
+        if($char -notmatch '[A-Za-z]' -or $char -eq ' '){
+            $badChar = $true
+            break
+        }
+
+    }
+
+    $firstLetter = $username[0]
+    $validFirstLetter = $firstLetter -match '[A-Za-z]'
+
+    if(-not $badChar  -and $username.Length -le 20  -and $validFirstLetter ){
+        Write-Host("$username is valid");
+    }else{
+        Write-Host("$username is Invalid");
+
+    }
+}