Code Typing · TypeScript
Type Guard
Validate unknown values with a predicate.
Difficulty: Intermediate · 15 Lines · License: public-domain
type User = {
id: number;
name: string;
email: string;
};
function isUser(value: unknown): value is User {
if (!value || typeof value !== 'object') return false;
const v = value as Record<string, unknown>;
Time0:00
Speed (WPM)0.0
Accuracy100.0%
Mistakes0
Live Keyboard
Next Key: T | Last Pressed: -
Progress: 0.0%
`
1
2
3
4
5
6
7
8
9
0
-
=
Q
W
E
R
T
Y
U
I
O
P
[
]
A
S
D
F
G
H
J
K
L
;
'
Z
X
C
V
B
N
M
,
.
/
Space
Timed Test Leaderboard
No results yet. Be the first to set a score.