Taking Someone Off by Name

Taking Someone Off by Name

In this lesson, you ported how the Monday script searches the rota by name, and found out what JavaScript does when a name isn’t there.

• Python asks with the in operator: "Kofi" in rota becomes rota.includes("Kofi"), a method on the array. Both answer yes for Kofi.
• Watch out: in JavaScript, "Kofi" in rota is false and 3 in rota is true, because the in operator asks about keys, such as an array’s positions, not its values.
• Python’s rota.index("Kofi") becomes rota.indexOf("Kofi"). Both return 3, counting from zero.
• For a name that isn’t there, Python’s index() raises ValueError: list.index(x): x not in list. JavaScript’s .indexOf() doesn’t raise: it returns -1, a value that means “not found”.
• Python’s count() has no array method to match.
• JavaScript arrays have no remove() method. The port builds one from two steps: .indexOf() finds the first match, and .splice() takes one item out from there.
• For a name that isn’t on the rota, .indexOf() returns -1, so the call becomes rota.splice(-1, 1). In Python, -1 is a position too, the last item. In JavaScript, square brackets don’t count from the end, but methods like .slice() and .splice() do. So it removes Marta, with no error.
• Python’s remove() can’t do this: its search raises first. In JavaScript, “not found” is a value, so check it before you splice.
• For arrays, .includes() and .indexOf() compare the way === does: the very same array, like Python’s is operator. Python’s in operator checks for equal contents instead. So an array of hours pairs won’t find a fresh [18, 8]: compare its parts, which the quiz practices.

Rui moved to the daytime team last month, and this week’s leave request is for him. Here’s the team lead’s Python:

rota = ["Dev", "Lena", "Ines", "Kofi", "Bea", "Marta"]
on_leave = "Rui"

rota.remove(on_leave)
print(rota)