instance method

String#hash

() -> ::Integer

hash → integer

static VALUE
rb_str_hash_m(VALUE str)
{
    st_index_t hval = rb_str_hash(str);
    return ST2FIX(hval);
}

Returns the integer hash value for self.

Two String objects that have identical content and compatible encodings also have the same hash value; see Object#hash and Encodings:

Example

s = 'foo'
h = s.hash       # => -569050784
h == 'foo'.hash  # => true
h == 'food'.hash # => false
h == 'FOO'.hash  # => false

s0 = "äöü"
s1 = s0.encode(Encoding::ISO_8859_1)
s0.encoding        # => #<Encoding:UTF-8>
s1.encoding        # => #<Encoding:ISO-8859-1>
s0.hash == s1.hash # => false

Related: see Querying.

See also #gsub! #hex #gsub #include? also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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