#1div#2#1div#2一个页面中有多个相同元素如#1br /#2#3lt;div#3gt;层1#3lt;/div#3gt;#1br /#2#3lt;div#3gt;层2#3lt;/div#3gt;#1br /#2#3lt;div#3gt;层3#3lt;/div#3gt;#3nb#7p;#1/div#2#1p#2#3nb#7p;#1/p#2#1p#2$("div")和c#7#7("width")#3nb#7p;#1/p#2#1p#2获得的是div中的第一元素的c#7#7属性;#1br /#2但是在用c#7#7()进行设置的时候,却对所有的div元素起作用。#3nb#7p;#1/p#2#1p#2#3nb#7p;#1/p#2#1/div#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2#1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2 #1#7cript #7rc="http://hm.baidu.c#5m/h.j#7?1#987#93c59264476bad398981#948#91f1a"#2#1/#7cript#2