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List Subscription

rascal-0.40.17

Synopsis​

Retrieve a list element via its index.

Syntax​

Exp₁ [ Exp₂ ]

Types​

//

Exp₁Exp₂Exp₁ [ Exp₂ ]
list[T₁]intT₁

Description​

List subscription uses the integer value of Exp₂ as index in the list value of Exp₁. The value of Exp₂ should be greater or equal 0 and less than the number of elements in the list. If this is not the case, the exception IndexOutOfBounds is thrown.

Examples​

Introduce a list, assign it to L and retrieve the element with index 1:

rascal>L = [10, 20, 30];
list[int]: [10,20,30]
rascal>L[1];
int: 20

Explore an error case:

rascal>L[5];
|prompt:///|(2,1,<1,2>,<1,3>): IndexOutOfBounds(5)
    at $shell$(|prompt:///|(0,5,<1,0>,<1,5>))
ok