jQuery入门(3) 设置DOM属性与获取DOM属性

    //设置input的value
    $("#edittext").val("99");
    //获取input的value
    var ret = $("#edittext").val();
    console.log(ret);

hello
hello
  

    //设置a标签的text
    $(".a").html("99");
    //获取a标签的text
    var     ret = $(".a").html();
    console.log(ret);

    //设置p元素的text
    $(".p").html("pppppp");
    //获取a元素的text
    ret = $(".p").html();
    console.log(ret);

    var $obj =$(".a");
    //设置css的color属性
    $obj.css("color","red"); 

    //获取css的color属性 color类型返回 rgb(255,0,0) 类型string
    var m_color = $obj.css("color");
    console.log(m_color+"类型:"+typeof m_color);

迭代：

    var $obj =$(".a");


    for(var x=0;x<$obj.length;x++)
    {
        $obj.eq(x).html("im index:"+x);

    }

    $obj= $(".a");//可省略 前面已经得到


    for(var x=0;x<$obj.length;x++)
    {
        console.log($obj.eq(x).html());

    }

val: function( value ) {
        var hooks, ret, isFunction,
            elem = this[ 0 ];

        if ( !arguments.length ) {
            if ( elem ) {
                hooks = jQuery.valHooks[ elem.type ] ||
                    jQuery.valHooks[ elem.nodeName.toLowerCase() ];

                if (
                    hooks &&
                    "get" in hooks &&
                    ( ret = hooks.get( elem, "value" ) ) !== undefined
                ) {
                    return ret;
                }

                ret = elem.value;

                return typeof ret === "string" ?

                    // handle most common string cases
                    ret.replace( rreturn, "" ) :

                    // handle cases where value is null/undef or number
                    ret == null ? "" : ret;
            }

            return;
        }

        isFunction = jQuery.isFunction( value );

        return this.each( function( i ) {
            var val;

            if ( this.nodeType !== 1 ) {
                return;
            }

            if ( isFunction ) {
                val = value.call( this, i, jQuery( this ).val() );
            } else {
                val = value;
            }

            // Treat null/undefined as ""; convert numbers to string
            if ( val == null ) {
                val = "";
            } else if ( typeof val === "number" ) {
                val += "";
            } else if ( jQuery.isArray( val ) ) {
                val = jQuery.map( val, function( value ) {
                    return value == null ? "" : value + "";
                } );
            }

            hooks = jQuery.valHooks[ this.type ] || jQuery.valHooks[ this.nodeName.toLowerCase() ];

            // If set returns undefined, fall back to normal setting
            if ( !hooks || !( "set" in hooks ) || hooks.set( this, val, "value" ) === undefined ) {
                this.value = val;
            }
        } );
    }