无法输出为啥
var info =[['小A','女',21,'大一'],['小B','男',23,'大三'],
['小C','男',24,'大四'],['小D','女',21,'大一'],
['小E','女',22,'大四'],['小F','男',21,'大一'],
['小G','女',22,'大二'],['小H','女',20,'大三'],
['小I','女',20,'大一'],['小J','男',20,'大三']];
for(var a=0;a<=10;a++){
if (info[a][3] == "大一") {
document.write(info[a]);
}
}