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@keima
Created November 11, 2019 07:08
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class X {
id: number = 3
}
class Y {
id: number = 9
}
var x = new X()
var y = new Y()
function isX(obj: any): obj is X {
return obj instanceof X
}
function isY(obj: any): obj is Y {
return obj instanceof Y
}
function hoge(obj: { id: number }): string {
// switchは使えない
if (isX(obj)) {
return `X: ${obj.id}`
} else if (isY(obj)) {
return `Y: ${obj.id}`
} else {
return `?: ${obj.id}`
}
}
console.log()
console.log()
alert(`${hoge(x)}, ${hoge(y)}`)
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