Code Typing · TypeScript
Tagged Union
Exhaustive handling of a discriminated type.
Difficulty: Intermediate · 15 Lines · License: public-domain
type Shape =
| { kind: 'circle'; radius: number }
| { kind: 'square'; side: number }
| { kind: 'rectangle'; width: number; height: number };
function area(shape: Shape): number {
switch (shape.kind) {
case 'circle':
return Math.PI * shape.radius ** 2;
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`
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