method
freeze
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freeze()
public
Prevents further modifications to obj. A RuntimeError will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?.
This method returns self.
a = [ "a", "b", "c" ] a.freeze a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen Array (RuntimeError) from prog.rb:3
Objects of the following classes are always frozen: Fixnum, Bignum, Float, Symbol.