//var version1 = document.all ? /(\d){1}/g.exec(window.navigator.userAgent.split(';')[1].replace(/^(\s){1,}|(\s){1,}$/g, ''))[1] : undefined; // 첫 번째 방법 var version1 = document.all ? /(\d){1}/g.exec(window.navigator.userAgent.split(';')[1])[1] : undefined; alert(version1); // my ie version // 두 번째 방법 var version2 = (function () { if (!document.all) return undefined; var v = 4 , div = document.createElement('div') , f = div.getElementsByTagName('i'); while (!f[0]) { div.innerHTML = '<!--[if IE ' + (v) + ']><i></i><![end if]-->'; v++; } v = v - 1; return v >= 4 ? v : undefined; })(); alert(version2); // my ie version // javascript 연산자 테스트 var num = 1; while (num = 0, num); alert(num); // 0