NSUserDefault存在-iPHONE SDK

Question

如果在那里保存NSUserDefault对象,我将如何检查"if"语句？我真的不确定怎么称呼它.所以这是一个很短的问题..

谢谢

Answer 1

if ([[NSUserDefaults standardUserDefaults] objectForKey:@"Foo"] != nil) {
  NSLog(@"an object is saved under \"Foo\"!");
}

Answer 2

戴夫的回答是正确的,但我会跳过nil的明确测试:

if ([[NSUserDefaults standardUserDefaults] objectForKey:@"Foo"]) {
    NSLog(@"An object is saved under \"Foo\"!");
}