Ruby String API Reference

`String`

8 methods

A String object holds and manipulates an arbitrary sequence of bytes, typically representing characters.

String#length -> Integer

Returns the number of characters in the string.

Returns

Integer

Example

ruby

"hello".length   # 5
"日本語".length   # 3

String#upcase -> String

Returns a copy of str with all lowercase letters replaced with their uppercase counterparts.

Returns

String

Example

ruby

"hello World".upcase  # "HELLO WORLD"

String#downcase -> String

Returns a copy of str with all uppercase letters replaced with their lowercase counterparts.

Returns

String

Example

ruby

"HELLO World".downcase  # "hello world"

String#split(pattern=nil, [limit]) -> Array

Divides str into substrings based on a delimiter, returning an array of substrings.

Parameters

Name	Type	Description
pattern	Regexp\|String\|nil	Delimiter pattern. nil splits on whitespace.
limit	Integer	Optional limit on number of splits.

Returns

Array

Example

ruby

"a,b,c".split(",")      # ["a", "b", "c"]
"  hello world  ".split  # ["hello", "world"]
"a-b-c".split("-", 2)    # ["a", "b-c"]

String#gsub(pattern, replacement) -> String

Returns a copy of str with all occurrences of pattern substituted with replacement.

Parameters

Name	Type	Description
pattern	Regexp\|String	Pattern to match.
replacement	String\|Hash	Replacement string or mapping.

Returns

String

Example

ruby

"hello world".gsub("o", "0")    # "hell0 w0rld"
"2024-01-01".gsub("-", "/")  # "2024/01/01"

String#strip -> String

Returns a copy of str with leading and trailing whitespace removed.

Returns

String

Example

ruby

"  hello  ".strip  # "hello"

String#include?(substring) -> bool

Returns true if str contains the given string or character.

Parameters

Name	Type	Description
substring	String	Substring to check for.

Returns

Boolean

Example

ruby

"hello world".include?("world")  # true
"hello".include?("z")            # false

String#chars -> Array

Returns an array of characters in str.

Returns

Array

Example

ruby

"hello".chars  # ["h", "e", "l", "l", "o"]

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