别了 JavaScript中的isXX系列

isNull: function(a){
return a === null;
},
isUndefined: function(a){
return a === undefined;
},
isNumber: function(a){
return typeof a === number;
},
isString: function(a){
return typeof a === string;
},
isBoolean: function(a){
return typeof a === boolean;
},
isPrimitive: function(b){
var a = typeof b;
return !!(b === undefined || b === null || a == boolean || a == number || a == string);
},
isArray: function(a){
return proto_obj.toString.call(a) === [object Array];
},
isFunction: function(a){
return proto_obj.toString.call(a) === [object Function];
},
isPlainObject: function(o){
if (!o || o === win || o === doc || o === doc.body) {
return false;
}
return isPrototypeOf in o && proto_obj.toString.call(o) === [object Object];
},
isWindow: function(o){
return o && typeof o === object && setInterval in o;
},
isEmptyObject: function(o){
for(var a in o) {
return false;
}
return true;
}