Iphone Games

Here I will show you how to use NSUserDefaults to save data.
This method is very simple but very slow, so it’s not good to use it to storage a big data.

Just add this line to setup :

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

And to read data use:

int value;
value = [prefs intForKey:@”value”];

To write data:

int value = 1;

[prefs setInteger:value forKey:@”value”];
[prefs synchronize];

Remember to synchronize after all saves, not at the end.

Of course you can write/read other data types.

From Mac Dev Center:

– setBool:forKey:
– setFloat:forKey:
– setInteger:forKey:
– setObject:forKey:
– setDouble:forKey:
– setURL:forKey:

In my apps I use it to check whether the app runs at the first time or not.

Just do something like this:

if ([prefs boolForKey:@”first_time”] == 0)
{
// First run
[prefs setBool:1 forKey:@”first_time”];
[prefs synchronize];
}
else
{
// Second run

}

It works becouse all unsaved data are from default 0.