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=== tests/cases/conformance/types/tuple/optionalTupleElements1.ts ===
type T1 = [number, string, boolean];
>T1 : [number, string, boolean]
type T2 = [number, string, boolean?];
>T2 : [number, string, (boolean | undefined)?]
type T3 = [number, string?, boolean?];
>T3 : [number, (string | undefined)?, (boolean | undefined)?]
type T4 = [number?, string?, boolean?];
>T4 : [(number | undefined)?, (string | undefined)?, (boolean | undefined)?]
type L1 = T1["length"];
>L1 : 3
type L2 = T2["length"];
>L2 : 3 | 2
type L3 = T3["length"];
>L3 : 3 | 2 | 1
type L4 = T4["length"];
>L4 : 0 | 3 | 2 | 1
type T5 = [number, string?, boolean]; // Error
>T5 : [number, (string | undefined)?, boolean]
function f1(t1: T1, t2: T2, t3: T3, t4: T4) {
>f1 : (t1: T1, t2: T2, t3: T3, t4: T4) => void
>t1 : T1
>t2 : T2
>t3 : T3
>t4 : T4
t1 = t1;
>t1 = t1 : T1
>t1 : T1
>t1 : T1
t1 = t2; // Error
>t1 = t2 : T2
>t1 : T1
>t2 : T2
t1 = t3; // Error
>t1 = t3 : T3
>t1 : T1
>t3 : T3
t1 = t4; // Error
>t1 = t4 : T4
>t1 : T1
>t4 : T4
t2 = t1;
>t2 = t1 : T1
>t2 : T2
>t1 : T1
t2 = t2;
>t2 = t2 : T2
>t2 : T2
>t2 : T2
t2 = t3; // Error
>t2 = t3 : T3
>t2 : T2
>t3 : T3
t2 = t4; // Error
>t2 = t4 : T4
>t2 : T2
>t4 : T4
t3 = t1;
>t3 = t1 : T1
>t3 : T3
>t1 : T1
t3 = t2;
>t3 = t2 : T2
>t3 : T3
>t2 : T2
t3 = t3;
>t3 = t3 : T3
>t3 : T3
>t3 : T3
t3 = t4; // Error
>t3 = t4 : T4
>t3 : T3
>t4 : T4
t4 = t1;
>t4 = t1 : T1
>t4 : T4
>t1 : T1
t4 = t2;
>t4 = t2 : T2
>t4 : T4
>t2 : T2
t4 = t3;
>t4 = t3 : T3
>t4 : T4
>t3 : T3
t4 = t4;
>t4 = t4 : T4
>t4 : T4
>t4 : T4
}
let t2: T2;
>t2 : T2
let t3: T3;
>t3 : T3
let t4: T4;
>t4 : T4
t2 = [42, "hello"];
>t2 = [42, "hello"] : [number, string]
>t2 : T2
>[42, "hello"] : [number, string]
>42 : 42
>"hello" : "hello"
t3 = [42, "hello"];
>t3 = [42, "hello"] : [number, string]
>t3 : T3
>[42, "hello"] : [number, string]
>42 : 42
>"hello" : "hello"
t3 = [42,,true]
>t3 = [42,,true] : [number, undefined, true]
>t3 : T3
>[42,,true] : [number, undefined, true]
>42 : 42
> : undefined
>true : true
t3 = [42];
>t3 = [42] : [number]
>t3 : T3
>[42] : [number]
>42 : 42
t4 = [42, "hello"];
>t4 = [42, "hello"] : [number, string]
>t4 : T4
>[42, "hello"] : [number, string]
>42 : 42
>"hello" : "hello"
t4 = [42,,true];
>t4 = [42,,true] : [number, undefined, true]
>t4 : T4
>[42,,true] : [number, undefined, true]
>42 : 42
> : undefined
>true : true
t4 = [,"hello", true];
>t4 = [,"hello", true] : [undefined, string, true]
>t4 : T4
>[,"hello", true] : [undefined, string, true]
> : undefined
>"hello" : "hello"
>true : true
t4 = [,,true];
>t4 = [,,true] : [undefined, undefined, true]
>t4 : T4
>[,,true] : [undefined, undefined, true]
> : undefined
> : undefined
>true : true
t4 = [];
>t4 = [] : []
>t4 : T4
>[] : []
|
