Builtins内置函数

• isNull
• len
• first
• last
• rest
• push
• puts
• fibonacci

isNull()

>> isNull([1,2,3][1])
false

>> isNull([1,2,3][3])
true

len()

>> len("hello")
5
>> len([1,2,3])
3

first()

>> first([1,2,3])
1

last()

>> last([1,2,3])
3

rest()

>> rest([1,2,3])
[2, 3]

push()

>> push([1,2,3], 4)
[1, 2, 3, 4]

puts()

>> puts("Hello", "Ledge")
"Hello"
"Ledge"
null

fibonacci()

>> fibonacci(35)
9227465