字符练习

    <script type="text/javascript">

        
/* indexOf()   用于查找字符串有是否有这个字符,返回索引
        var the_email = prompt("what\'s your email address?","");
        var temp = the_email.indexOf('@');
        if(temp==-1){
            alert("your email have not @ char.");
        }
*/

/* charAt()  可以返回字串中的某个字符
    var the_word = "monkey";
    var the_last_word = the_word.charAt(the_word.length-1); 
    alert(the_last_word);  //output y
*/

/*

substring()  可以截取一个字串中的几个字符，而不是单个。语法 : substring(form,to)  length = to -form, to 的长度是整个字符长度
    var the_string = "monkey";
    var cut_it =  the_string.substring(3,4);
    alert(cut_it);  //output k
*/


/*
    var the_string = "http://www.webmonkey.com/javascript/index.html";
    var first_slashes = the_string.indexOf("//");
//    alert(first_slashes); output 5
    var start_domain = first_slashes+2;
    
    var without_resource = the_string.substring(start_domain,the_string.length);
//    alert(without_resource); output www.webmonkey.com/javascript/index.html
    var sec_slash = without_resource.indexOf("/");
    var domain = without_resource.substring(0,sec_slash);
    alert(domain); //output www.webmonkey.com
*/

/*  split()  将字符转换成数组
    var my_friends ="trixie,moxie,sven,guido,hermes";
    var friend_array = my_friends.split(",");
    
    for(var i=0;i<friend_array.length;i++){
        document.write(friend_array[i]+"<br/>");
    }
*/

/*
    var the_string = "http://www.webmonkey.com/javascript/index.html";
    var first_split = the_string.split("//");
    var without_resource = first_split[1];
    var sec_split = without_resource.split("/");
    var domain = sec_split[0];
    alert(domain);
*/

</script>