大写第一个字母

<script>
    // 大写第一个字母
    function _upperCase1st(string) {
        return string.replace(/^(\w)/, function(w) {
            alert(w)
            return w.toUpperCase();
        });
    }
    var str = _upperCase1st('abcdef');
    document.write(str);
</script>

 

<p id="test"></p>
<p id="split"></p>
<script type="text/javascript">
function reg_replace(){
    var str = "welcome to visit www.nowamagic.net";
    var test = document.getElementById("test");
    regex = new RegExp("i","g");//g 修饰符用于执行全局匹配（查找所有匹配而非在找到第一个匹配后停止）。
    test.innerHTML = str.replace(regex,"<span style='background-color:orange'>I</span>");
    //alert(str.replace(regex,"I"));
}

function reg_split()
{
    var str = "welcome to visit www.nowamagic.net";
    var test = document.getElementById("split");
    regex = new RegExp("i","g");
    test.innerHTML = str.replace(regex,'&');
    //test.innerHTML = str.split(regex);
    //alert(str.replace(regex,"I"));
}

reg_replace();

reg_split();
</script>