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Let regex;
/* shorthand character classes */
regex = /d/; // matches any digit, short for [0-9]
regex = /D/; // matches non-digits, short for [^0-9]
regex = /S/; // matches non-white space character
regex = /s/; // matches any white space character
regex = /w/; // matches character, short for [a-zA-Z_0-9]
regex = /W/; // matches non-word character [^w]
regex = /b/; // Matches a word boundary where a word character is [a-zA-Z0-9_]
These meta characters boast a pre-defined meaning and make various typical patterns easier to use.
/* matching using quantifiers */
regex= /X./; // matches any character
regex= /X*/; // Matches zero or several repetitions of letter X, is short for {0,}
regex= /X+-/; // matches one or more repetitions of letter X, is short for {1,}
regex= /X?/; // finds no or exactly one letter X, is short for is short for {0,1}.
regex= // d{3}; // matches three digits. {} describes the order of the preceding liberal
regex= // d{1,4} ; // means d must occur at least once and at a maximum of four
A quantifies helps developers to define how often an element occurs.
/* character ranges */
regex = /[a-z]/; // matches all lowercase letters
regex = /[A-Z]/; // matches all uppercase letters
regex = /[e-l]/; // matches lowercase letters e to l (inclusive)
regex = /[F-P]/; // matches all uppercase letters F to P (inclusive)
regex = /[0-9]/; // matches all digits
regex = /[5-9]/; // matches any digit from 5 to 9 (inclusive)
regex = / [a-d1-7]/; // matches a letter between a and d and figures from 1 to 7, but not d1
regex = /[a-zA-Z]/; // matches all lowercase and uppercase letters
regex = /[^a-zA-Z]/; // matches non-letters
/* matching using anchors */
regex = / ^The/; // matches any string that starts with “The”
regex = / end$/; // matches a string that ends with end
regex = / ^The end$/; // exact string match starting with “The” and ending with “End”
/* escape characters */
regex = / a/; // match a bell or alarm
regex = / e/; // matches an escape
regex = / f/; // matches a form feed
regex = / n/; // matches a new line
regex = / Q…E/; // ingnores any special meanings in what is being matched
regex = / r/; // matches a carriage return
regex = / v/; // matches a vertical tab
It is critical to note that escape characters are case sensitive
/* matching using flags */
regex = / i/; // ignores the case in pattern ( upper and lower case allowed)
regex = / m/; // multi-line match
regex = / s/; // match new lines
regex = / x/; // allow spaces and comments
regex = / j/; // duplicate group names allowed
regex = / U/; // ungreedy match
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// "/^[a-zA-Z]+$/" for alphabetics;
// "/^[0-9]+$/" for numerics;
// "/^[a-zA-Z0-9]+$/" for alphanumerics;
// "/^\pL+$/u" for uni alphas;
// "/^\pN+$/u" for uni numerics;
// "/^[\pL\pN]+$/u" for uni alphanumerics;
regex pattern
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Only lowercase letters and numbers are allowed. Spaces are also not allowed
pattern="^[a-z0-9_\-]+$"
Must contain at least one number and one uppercase and lowercase letter, and at least 8 or more characters
pattern="(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,}"
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/[A-Z]/ : 'must contain one uppercase'
/([a-z])/ : 'must contain one lowercase'
/(\d)/ : 'must contain one number'
/(\W)/ : 'must contain one special character'
Let regex;
/* shorthand character classes */
regex = /d/; // matches any digit, short for [0-9]
regex = /D/; // matches non-digits, short for [^0-9]
regex = /S/; // matches non-white space character
regex = /s/; // matches any white space character
regex = /w/; // matches character, short for [a-zA-Z_0-9]
regex = /W/; // matches non-word character [^w]
regex = /b/; // Matches a word boundary where a word character is [a-zA-Z0-9_]
These meta characters boast a pre-defined meaning and make various typical patterns easier to use.
/* matching using quantifiers */
Let regex;
/* shorthand character classes */
regex = /d/; // matches any digit, short for [0-9]
regex = /D/; // matches non-digits, short for [^0-9]
regex = /S/; // matches non-white space character
regex = /s/; // matches any white space character
regex = /w/; // matches character, short for [a-zA-Z_0-9]
regex = /W/; // matches non-word character [^w]
regex = /b/; // Matches a word boundary where a word character is [a-zA-Z0-9_]
These meta characters boast a pre-defined meaning and make various typical patterns easier to use.
/* matching using quantifiers */
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import re
reload (re)
r = re.compile("([0-9]+)([a-zA-Z]+)([0-9]+)")
m = r.match("123ab1234")
if m:
print m.group(1)
print m.group(2)
print m.group(3)
else:
print "no match"
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const text = 'Образец text на русском языке';
const regex = /[\u0400-\u04FF]+/g;
const match = regex.exec(text);
console.log(match[0]); // logs 'Образец'
console.log(regex.lastIndex); // logs '7'
const match2 = regex.exec(text);
console.log(match2[0]); // logs 'на' [did not log 'text']
console.log(regex.lastIndex); // logs '15'
// and so on