how to replace previous data with new data in arrays

i am getting some information from .net webserver and save them in NSuserdefaults.

for that my code is

[[NSUserDefaults standardUserDefaults] setObject:resultData_agent forKey:@"agentid"];
    [[NSUserDefaults standardUserDefaults] setObject:array1 forKey:@"loanoff_id"];
    [[开发者_如何学GoNSUserDefaults standardUserDefaults] setObject:array2 forKey:@"agentnames"];
    [[NSUserDefaults standardUserDefaults] setObject:array3 forKey:@"agentemail"];
    [[NSUserDefaults standardUserDefaults] setObject:array4 forKey:@"agentphone"];

to get them i use the fallowing code

agentids = [[NSUserDefaults standardUserDefaults] arrayForKey:@"agentid"];
    loanofficerid = [[NSUserDefaults standardUserDefaults] arrayForKey:@"loanoff_id"];
    agentnames = [[NSUserDefaults standardUserDefaults] arrayForKey:@"agentnames"];
    agentemails = [[NSUserDefaults standardUserDefaults] arrayForKey:@"agentemail"];
    agentphone = [[NSUserDefaults standardUserDefaults] arrayForKey:@"agentphone"];

here these 5 are arrays.

i need to repeat this process for every 5 min.

here i got a problem data is not replaced in arrays they added to existing data.

for eg:initially in agetids i have 101,when i repeat this process it shows 101,101

but i need replace these values with existing one.

i try using NSMutable array but it shows warning at agentids = [[NSUserDefaults standardUserDefaults] arrayForKey:@"agentid"];

how can i done can any one please help me.

Thank u in advance.

I think you get NSArray from NSUserDefault that why you having a warning.

use this,

agentids = [[[NSUserDefaults standardUserDefaults] arrayForKey:@"agentid"] mutableCopy];

and before inserting new data you need to remove previous objects from this.use removeAllObjects method for this.