instance method

String#tr

(::String::selector source, ::string relpacement) -> ::String

tr(selector, replacements) → new_string

static VALUE
rb_str_tr(VALUE str, VALUE src, VALUE repl)
{
    str = str_duplicate(rb_cString, str);
    tr_trans(str, src, repl, 0);
    return str;
}

Returns a copy of self with each character specified by string selector translated to the corresponding character in string replacements. The correspondence is positional:

Each occurrence of the first character specified by selector is translated to the first character in replacements.
Each occurrence of the second character specified by selector is translated to the second character in replacements.
And so on.

Example:

Example

'hello'.tr('el', 'ip') #=> "hippo"

If replacements is shorter than selector, it is implicitly padded with its own last character:

Example

'hello'.tr('aeiou', '-')   # => "h-ll-"
'hello'.tr('aeiou', 'AA-') # => "hAll-"

Arguments selector and replacements must be valid character selectors (see Character Selectors), and may use any of its valid forms, including negation, ranges, and escapes:

Example

'hello'.tr('^aeiou', '-')       # => "-e--o"     # Negation.
'ibm'.tr('b-z', 'a-z')          # => "hal"       # Range.
'hel^lo'.tr('\^aeiou', '-')     # => "h-l-l-"    # Escaped leading caret.
'i-b-m'.tr('b\-z', 'a-z')       # => "ibabm"     # Escaped embedded hyphen.
'foo\\bar'.tr('ab\\', 'XYZ')    # => "fooZYXr"   # Escaped backslash.

Related: see Converting to New String.

Ruby version changes

3.0
- The following methods now return or yield String instances instead of subclass instances when called on subclass instances: [Bug #10845]

See also #tr! #to_sym #to_str #tr_s also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

‹ prev#to_sym next ›#tr!