javascript - 正規表現を使用してWebKitバージョン525以下を検出する

Answer 1

I'm providing this with the usual caveats: you should use this only if you are absolutely sure there is no way to test the actual feature you want to use that differs between WebKit versions:

function checkWebKit() {
    var result = /AppleWebKit\/([\d.]+)/.exec(navigator.userAgent);
    if (result) {
        return parseFloat(result[1]);
    }
    return null;
}