String — Character String class


String is one of Ruby’s basic datatypes, which contain arbitrary sequences of bytes. String can contain \0.

Included Module

Enumerable, Comparable

Class Method


Creates a string.

Instance Methods

Methods of the String class ending in ! modify their receiver and return a string if modification took place, otherwise nil. Methods without a ! return a modified copy of the string.

~ s

Attempts to match pattern s against the $_ variable. This method is obsolete.

s % arg

An abbreviated form of sprintf(s, arg...). Multiple elements are specified using an array.

s * n

Returns a string consisting of s copied end to end n times.

s + str

Returns a string with str concatenated to s.

s << str

Concatenates str to s.

s =~ x

Performs a regular expression match. If x is a string, it’s turned into a Regexp object.


Returns the code of the character at position n. If n is negative, it’s counted as an offset from the end of the string.

s[n, len]

Returns a partial string.

"bar"[1..2]   # => "ar"
"bar"[1..-1]  # => "ar"
"bar"[-2..2]  # => "ar"
"bar"[-2..-1] # => "ar"
"bar"[1,2]    # => "ar"
"bar"[-1, 1]  # => "r"

Replaces the n th element in the string with value. value may be a character code or string.

s[n, len]=str

Replaces a part of the string with str.


Returns a copy of s with the first character converted to uppercase and the remainder to lowercase.

"fooBar".capitalize            # => "Foobar"

Returns a ...

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