查看一个简单的jQuery的例子来遍历一个JavaScript数组对象。
- var json = [
- {"id":"1","tagName":"apple"},
- {"id":"2","tagName":"orange"},
- {"id":"3","tagName":"banana"},
- {"id":"4","tagName":"watermelon"},
- {"id":"5","tagName":"pineapple"}
- ];
-
- $.each(json, function(idx, obj) {
- alert(obj.tagName);
- });
上面的代码片断工作正常，提示 “apple”, “orange” … 等，如预期一样。
问题: JSON 字符串
下面的例子中，声明了一个JSON字符串（随附单或双引号）直接地。
-
var json = ‘[{"id":"1","tagName":"apple"},{"id":"2","tagName":"orange"},
-
{"id":"3","tagName":"banana"},{"id":"4","tagName":"watermelon"},
-
{"id":"5","tagName":"pineapple"}]‘;
-
-
$.each(json, function(idx, obj) {
-
alert(obj.tagName);
-
});
在Chrome中，它显示在控制台下面的错误：
Uncaught TypeError: Cannot use ‘in‘ operator to search for ‘156‘
in [{"id":"1","tagName":"apple"}...
解决方案：JSON字符串转换为JavaScript对象。
要修复它，通过标准JSON.parse()或jQuery 的 $.parseJSON 将其转换为JavaScript对象。
-
var json = ‘[{"id":"1","tagName":"apple"},{"id":"2","tagName":"orange"},
-
{"id":"3","tagName":"banana"},{"id":"4","tagName":"watermelon"},
-
{"id":"5","tagName":"pineapple"}]‘;
-
-
$.each(JSON.parse(json), function(idx, obj) {
-
alert(obj.tagName);
-
});
-
-
-
-
$.each($.parseJSON(json), function(idx, obj) {
-
alert(obj.tagName);
-
});
