When can I say I have mastered a programming language?

When can I say I have mastered a programming language?

a year ago
Anonymous $5YzO3NGzaX
Last Seen
17 minutes ago
Reputation
0
Spam
0.000
Last Seen
51 minutes ago
Reputation
0
Spam
0.000
Last Seen
12 minutes ago
Reputation
0
Spam
0.000
Last Seen
3 hours ago
Reputation
0
Spam
0.000
Last Seen
2 hours ago
Reputation
0
Spam
0.000
Last Seen
42 minutes ago
Reputation
0
Spam
0.000