자바스크립트 정규식 예제

function RegMerge() {
    var expr = [];
    for ( var i = 0; i < arguments.length; i++ )
        expr.push( arguments[i].toString().replace(/^\/|\/\w*$/g, "") );
    return new RegExp( "(?:" + expr.join("|") + ")" );
}
var re = RegMerge( /Ninj(a|itsu)/, /Sword/, /Katana/ );
assert( re.test( "Ninjitsu" ),"Verify that the new expression works." );
assert( re.test( "Katana" ),"Verify that the new expression works." );

//The difference between a global and local search with match
var html = "
Hello world!
";
var results = html.match(/<(\/?)(\w+)([^>]*?)>/);
assert( results[0] == "
", "The entire match." );
assert( results[1] == "", "The (missing) slash." );
assert( results[2] == "div", "The tag name." );
assert( results[3] == " class='test'", "The attributes." );

var all = html.match(/<(\/?)(\w+)([^>]*?)>/g);
assert( all[0] == "
", "Opening div tag." );
assert( all[1] == "", "Opening b tag." );
assert( all[2] == "", "Closing b tag." );
assert( all[3] == "", "Opening i tag." );
assert( all[4] == "", "Closing i tag." );
assert( all[5] == "
", "Closing div tag." );


//Using the exec method to do both capturing and a global search
var html = "
Hello world!
";
var tag = /<(\/?)(\w+)([^>]*?)>/g, match;
var num = 0;
while ( (match = tag.exec(html)) !== null ) {
    assert( match.length == 4,"Every match finds each tag and 3 captures." );
    num++;
}
assert( num == 6, "3 opening and 3 closing tags found." );

//Using back-references to match the contents of an HTML tag.
var html = "Hello world!";
var tag = /<(\w+)([^>]+)>(.*?)<\/\1>/g;

var match = tag.exec(html);
assert( match[0] == "Hello","The entire tag, start to finish." );
assert( match[1] == "b", "The tag name." );
assert( match[2] == " class='hello'", "The tag attributes." );
assert( match[3] == "Hello", "The contents of the tag." );

//Matching multiple words using a non-capturing group
var re = /((?:ninja-)+)sword/;
var ninjas = "ninja-ninja-sword".match(re);
assert( ninjas[1] == "ninja-ninja-","Match both words, without extra capture." );

//A technique for compressing a query string.
function compress(data)
{
    var q = {}, ret = [];

    data.replace(/([^=&]+)=([^&]*)/g, function(m, key, value){
        q[key] = (q[key] ? q[key] + "," : "") + value;
        return "";
    });

    for ( var key in q ) {
        ret.push( key + "=" + q[key] );
    }

    return ret.join("&");
}
assert( compress("foo=1&foo=2&blah=a&blah=b&foo=3") == "foo=1,2,3&blah=a,b", "Verify the compression." );

//trim
function trim(str)
{
    return str.replace(/^\s+|\s+$/g, "");
}

function trim(str)
{
    return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
}

function trim(str) {
    var str = str.replace(/^\s\s*/, ''),
    ws = /\s/, i = str.length;
    while (ws.test(str.charAt(--i)));
    return str.slice(0, i + 1);
}

//unicode
var str = "\u0130\u0131\u0132";
assert( ("#" + str).match(new RegExp("#([\\w\u0128-\uFFFF_-]+)")),"Verify that our RegExp matches a Unicode selector." );