Referência JavaScript RegExp
Objeto RegExp
Uma expressão regular é um padrão de caracteres.
O padrão é usado para fazer funções de "pesquisar e substituir" de correspondência de padrões no texto.
Em JavaScript, um objeto RegExp é um padrão com Propriedades e Métodos .
Sintaxe
/pattern/modifier(s);
Exemplo
let pattern = /w3schools/i;
Exemplo explicado:
w3escolas | O padrão para procurar |
---|---|
/w3escolas/ | Uma expressão regular |
/w3escolas/i | Uma expressão regular que não diferencia maiúsculas de minúsculas |
Para um tutorial sobre Expressões Regulares, leia nosso Tutorial JavaScript RegExp .
Suporte ao navegador
/regexp/
é um recurso ECMAScript1 (ES1).
ES1 (JavaScript 1997) é totalmente suportado em todos os navegadores:
Chrome | IE | Edge | Firefox | Safari | Opera |
Yes | Yes | Yes | Yes | Yes | Yes |
Modificadores
Os modificadores são usados para realizar pesquisas globais e que não diferenciam maiúsculas de minúsculas:
Modifier | Description |
---|---|
g | Perform a global match (find all matches rather than stopping after the first match) |
i | Perform case-insensitive matching |
m | Perform multiline matching |
Suportes
Colchetes são usados para encontrar um intervalo de caracteres:
Expression | Description |
---|---|
[abc] | Find any character between the brackets |
[^abc] | Find any character NOT between the brackets |
[0-9] | Find any character between the brackets (any digit) |
[^0-9] | Find any character NOT between the brackets (any non-digit) |
(x|y) | Find any of the alternatives specified |
Metacaracteres
Metacaracteres são caracteres com um significado especial:
Metacharacter | Description |
---|---|
. | Find a single character, except newline or line terminator |
\w | Find a word character |
\W | Find a non-word character |
\d | Find a digit |
\D | Find a non-digit character |
\s | Find a whitespace character |
\S | Find a non-whitespace character |
\b | Find a match at the beginning/end of a word, beginning like this: \bHI, end like this: HI\b |
\B | Find a match, but not at the beginning/end of a word |
\0 | Find a NULL character |
\n | Find a new line character |
\f | Find a form feed character |
\r | Find a carriage return character |
\t | Find a tab character |
\v | Find a vertical tab character |
\xxx | Find the character specified by an octal number xxx |
\xdd | Find the character specified by a hexadecimal number dd |
\udddd | Find the Unicode character specified by a hexadecimal number dddd |
Quantificadores
Quantifier | Description |
---|---|
n+ | Matches any string that contains at least one n |
n* | Matches any string that contains zero or more occurrences of n |
n? | Matches any string that contains zero or one occurrences of n |
n{X} | Matches any string that contains a sequence of X n's |
n{X,Y} | Matches any string that contains a sequence of X to Y n's |
n{X,} | Matches any string that contains a sequence of at least X n's |
n$ | Matches any string with n at the end of it |
^n | Matches any string with n at the beginning of it |
?=n | Matches any string that is followed by a specific string n |
?!n | Matches any string that is not followed by a specific string n |
Propriedades do objeto RegExp
Property | Description |
---|---|
constructor | Returns the function that created the RegExp object's prototype |
global | Checks whether the "g" modifier is set |
ignoreCase | Checks whether the "i" modifier is set |
lastIndex | Specifies the index at which to start the next match |
multiline | Checks whether the "m" modifier is set |
source | Returns the text of the RegExp pattern |
Métodos de objeto RegExp
Method | Description |
---|---|
compile() | Deprecated in version 1.5. Compiles a regular expression |
exec() | Tests for a match in a string. Returns the first match |
test() | Tests for a match in a string. Returns true or false |
toString() | Returns the string value of the regular expression |