var testStr = '[{"aa":"a1","bb":"b1","cc":"c1","dd":"d1"},{"aa":"a2","bb":"b2","cc":"c2","dd":"d2"},{"aa":"a3","bb":"b3","cc":"c3","dd":"d3"},{"aa":"a4","bb":"b4","cc":"c4","dd":"d4"},{"aa":"a5","bb":"b5","cc":"c5","dd":"d5"}]';
这个testStr是什么类型？如何给它添加新的内容？
补充：这样this.objectlist = eval('('+testStr+')');，有什么用哦？eval后得到的什么？
这是json格式的字符串
<!DOCTYPE html>
<html>
<body>
<script>
var testStr = '[{"aa":"a1","bb":"b1","cc":"c1","dd":"d1"},{"aa":"a2","bb":"b2","cc":"c2","dd":"d2"},{"aa":"a3","bb":"b3","cc":"c3","dd":"d3"},{"aa":"a4","bb":"b4","cc":"c4","dd":"d4"},{"aa":"a5","bb":"b5","cc":"c5","dd":"d5"}]';
var jsontext = eval('('+testStr+')');
for(var i=0;i<jsontext.length;i++){
document.write(jsontext[i].aa+',');
jsontext[i]['添加内容']='cccc';
document.write(jsontext[i].添加内容+',');
}
</script>
</body>
</html>
得到的是json对象，就可以直接用 objectlist.xxx访问里面的对象
testStr是字符串，eval后得到json对象
是json字符串，你可以在前台直接解析她！
testStr是json，要给他添加新内容，如果新内容少的话可以按照上面的格式直接拼进去，新内容多得话可以用JsonArray或者JsonObject等类将新的内容自动转换为json再添进去。具体可以问度娘了
这个testStr如果是在html里面就是一个var类型也就是string类型，
eval计算字符串，得到的是一个数组不是JSON
也就是这个数组 去掉引号[{"aa":"a1","bb":"b1","cc":"c1","dd":"d1"},{"aa":"a2","bb":"b2","cc":"c2","dd":"d2"},{"aa":"a3","bb":"b3","cc":"c3","dd":"d3"},{"aa":"a4","bb":"b4","cc":"c4","dd":"d4"},{"aa":"a5","bb":"b5","cc":"c5","dd":"d5"}];
testStr,是一个String类型，用eval计算后是Ojbect对象，
var testStr = '[{"aa":"a1","bb":"b1","cc":"c1","dd":"d1"},{"aa":"a2","bb":"b2","cc":"c2","dd":"d2"},{"aa":"a3","bb":"b3","cc":"c3","dd":"d3"},{"aa":"a4","bb":"b4","cc":"c4","dd":"d4"},{"aa":"a5","bb":"b5","cc":"c5","dd":"d5"}]';
alert(typeof(testStr));---->string
var s= eval('('+testStr+')');
alert(s)----->则是一个数组对象
alert(s[0].aa);---->a1
alert(s[1].aa);---->a2
json数据包
eval后得到
{"aa":"a1","bb":"b1","cc":"c1","dd":"d1"},{"aa":"a2","bb":"b2","cc":"c2","dd":"d2"},{"aa":"a3","bb":"b3","cc":"c3","dd":"d3"},{"aa":"a4","bb":"b4","cc":"c4","dd":"d4"},{"aa":"a5","bb":"b5","cc":"c5","dd":"d5"}
var 是弱数据类型，后边的数据是什么类型它就是什么类型