Pike: index

NAME: index - get/set an element in an array/string/mapping/object
SYNTAX: a [ b ] or a [ b ] = c or a -> b
DESCRIPTION: This operator does a lookup in 'a' to find the element named 'b' in

'a'. The last syntax (a->b) is equal to a [ "b" ]. Different usage

applies to different types.

Strings With strings, the index operator can only be used to get values

not change them. The index must be an integer, and the return value will be the ascii value of the corresponding character in the string. The first character is numbered 0.

Arrays As with strings, arrays can only be indexed on integers. However, values can also be changed by using indexing on the left side of an assignment. The values in the array can have any type. As with strings, the first index is 0.

Mappings Mappings can be indexed on any type of value, quite often they are indexed on strings. Values can be changed as with arrays. Mappings do not have a fixed size, nor do they have a specific order in which the values are stored. If you attempt to set a value in a mapping that does not already exists, the mapping will grow to include the new value. There is no 'first' index for mappings.

Multisets Multisets can be also be indexed on any value, but the return value only reflects a true/false status depending on weather that index was present in the multiset. As with mappings, multisets will grow when you try to set a value in it that is does not already exists. However multisets will only grow if the inserted 'c' is nonzero.

Object Objects can only be indexed on strings. It then gets/sets the value of the variable with that name. If the 'variable' isn't a variable at all, but a function it will return a pointer to that function but you can't change it.
EXAMPLES: "foobar"[2] returns 111 /* ascii for 'o' */ "foobar"[0] returns 102 /* ascii for 'f' */ ({1,2,3})[1] returns 2 ([1:2})[1] returns 2 (<1,2,3>)[2] returns 1
KEYWORDS: operators
SEE ALSO: index

This operator does a lookup in 'a' to find the element named 'b' in
'a'. The last syntax (a->b) is equal to a [ "b" ]. Different usage
applies	to different types.

Strings	With strings, the index operator can only be used to get values
	not change them. The index must be an integer, and the return value will be the ascii value of the corresponding character in the string. The first character is numbered 0.
Arrays	As with strings, arrays can only be indexed on integers. However, values can also be changed by using indexing on the left side of an assignment. The values in the array can have any type. As with strings, the first index is 0.
Mappings	Mappings can be indexed on any type of value, quite often they are indexed on strings. Values can be changed as with arrays. Mappings do not have a fixed size, nor do they have a specific order in which the values are stored. If you attempt to set a value in a mapping that does not already exists, the mapping will grow to include the new value. There is no 'first' index for mappings.
Multisets	Multisets can be also be indexed on any value, but the return value only reflects a true/false status depending on weather that index was present in the multiset. As with mappings, multisets will grow when you try to set a value in it that is does not already exists. However multisets will only grow if the inserted 'c' is nonzero.
Object	Objects can only be indexed on strings. It then gets/sets the value of the variable with that name. If the 'variable' isn't a variable at all, but a function it will return a pointer to that function but you can't change it.

"foobar"[2]	returns 111 /* ascii for 'o' */
"foobar"[0]	returns 102 /* ascii for 'f' */
({1,2,3})[1]	returns 2
([1:2})[1]	returns 2
(<1,2,3>)[2]	returns 1