
var list = [0, 1, 2, 3, 4]
System.print(list.indexOf(4))   // expect: 4
System.print(list.indexOf(2))   // expect: 2
System.print(list.indexOf(3))   // expect: 3
System.print(list.indexOf(0))   // expect: 0
System.print(list.indexOf(100)) // expect: -1
System.print(list.indexOf(-1))  // expect: -1