Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?<=^[\\t ]*|[\\n;](?:[\\t ]*(?:\\w+ )?)?)export(?:(?: *(?<type>type) *)|[\\t\\n ]*)(?<exports>(?:\\*(?: +as +\\S+)?)|\\S+|(?:\\{[\\w\\t\\n\\r \"$'*,./-]+?\\}))[\\t ]*from[\\t ]*[\"']\\s*(?<specifier>(?:(?<=' *)[^']*[^\\s'](?= *'))|(?:(?<=\" *)[^\"]*[^\\s\"](?= *\"))) *[\"']"; final String string = "export { default } from './make'\n" + "export { \n" + " DEFAULTS,\n" + " plugin as default,\n" + " type Options\n" + "} from './plugin'\n" + "export type { Config, Result } from './interfaces'\n" + "export type { default as Options } from './options'\n" + "export type Foo from '#foo'\n\n" + "export type * from \"./spaceship\"\n" + "export type * as vehicles from \"./spaceship\"\n" + "export * as constants from './constants'\n" + "export * from './interfaces'\n" + "export * from './lib'\n" + "export * from './types'\n" + "export * from \"module-name\";\n" + "export * as name1 from \"module-name\";var g;export{name1}from\"module-name\";\n" + "export { name1, /* */ nameN } from \"module-name\";\n" + "export { import1 as name1, import2 as name2, /* */ nameN } from \"module-name\";\n" + "export { default, /* */ } from \"module-name\";\n\n" + "declare module 'module-name' {\n" + " export { default } from './make'\n" + " export { \n" + " DEFAULTS,\n" + " plugin as default,\n" + " type Options\n" + " } from './plugin'\n" + "}\n\n" + " export {\n" + " DEFAULTS,\n" + " plugin as default,\n" + " type Options\n" + " }\n" + " export { defineBuildConfig, type BuildConfig } from \"#src\"\n" + " export type {\n" + " JsonObject,\n" + " LiteralUnion,\n" + " Nullable\n" + " } from '@flex-development/tutils'\n" + " export {\n" + " addFive,\n" + " addFour,\n" + " addThree,\n" + " addTwo,\n" + " squareFive,\n" + " squareFour,\n" + " squareThree,\n" + " squareTwo\n" + " } from './lib'\n" + " export * as constants from \"./constants\"\n" + " export type { default as Options }\n" + " export type { default as Options } from \"./options\"\n" + " export * from './utils'\n" + " export interface User {}\n" + " export abstract class House {}\n" + " export const { name1, name2: bar } = o;\n" + " export const [ name1, name2 ] = array;\n" + " export default async function foo() {}\n" + " export default foo\n" + " export default 1 + 1;\n" + " export type { Config, Result }\n\n" + "\"export type { default as Statement }\"\n\n" + "export { name1, /* */ nameN };\n" + "export { variable1 as name1, variable2 as name2, /* */ nameN };\n" + "export { variable1 as \"string name\" };\n" + "export { name1 as default /*, */ };\n" + "export type { CompilerOptionsJson as default };\n" + "export { default }\n" + "export { \n" + " DEFAULTS,\n" + " plugin as default,\n" + " type Options\n" + "}\n" + "export type { Config, Result }\n" + "export type { default as Options }\n\n" + "var g;export{name1}; export{name1}\n" + "export { name1, /* */ nameN }\n" + "export { import1 as \", import2 as name2, /* */ nameN }\n" + "export { default, /* */ }\n\n" + "// export * from './constants'\n\n" + "// export type { default as Statement }\n\n\n" + "/**\n" + " *\n" + " * @example\n" + " * export { default }\n" + " * export { Config, Result }\n" + " * export type { default as Options }\n" + " */\n\n" + "// export * from './constants'\n\n" + "//export type { default as Statement } from './statement'\n\n" + "/* export type { default as Statement } from './statement' */\n\n" + "/*export type { default as Statement } from './statement' */\n\n" + "/*\n" + " * @example\n" + " * export * from './constants'\n" + " */\n\n" + "/**\n" + " * @example\n" + " * export * from './constants'\n" + " */\n\n" + "/**\n" + " *\n" + " * @example\n" + " * export { default } from './make'\n" + " * export { Config, Result } from './interfaces'\n" + " * export type { default as Options } from './options'\n" + " */\n\n" + "export type { Config, Result } from './interfaces'"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html