- * array.sort! -> self

- * array.sort! {|a, b| ... } -> self

- * Returns +self+ with its elements sorted in place.

- *

- * With no block, compares elements using operator <tt>#<=></tt>

- * (see Comparable):

- *

- * a = 'abcde'.split('').shuffle

- * a # => ["e", "b", "d", "a", "c"]

- * a.sort!

- * a # => ["a", "b", "c", "d", "e"]

- *

- * With a block, calls the block with each element pair;

- * for each element pair +a+ and +b+, the block should return an integer:

- *

- * - Negative when +b+ is to follow +a+.

- * - Zero when +a+ and +b+ are equivalent.

- * - Positive when +a+ is to follow +b+.

- *

- * Example:

- *

- * a = 'abcde'.split('').shuffle

- * a # => ["e", "b", "d", "a", "c"]

- * a.sort! {|a, b| a <=> b }

- * a # => ["a", "b", "c", "d", "e"]

- * a.sort! {|a, b| b <=> a }

- * a # => ["e", "d", "c", "b", "a"]

- *

- * When the block returns zero, the order for +a+ and +b+ is indeterminate,

- * and may be unstable:

- *

- * a = 'abcde'.split('').shuffle

- * a # => ["e", "b", "d", "a", "c"]

- * a.sort! {|a, b| 0 }

- * a # => ["d", "e", "c", "a", "b"]