ios - How can I find the average of 10 values in an array in Objective-C -

i attempting find average of 10 signal strength values have been inserted array periodically nstimer function. know timer working due console logs, array of 10 values not. there small error in code or potentially issue if/else statement?

- (ibaction)getsignalavg:(id)sender {      mytimer = [nstimer scheduledtimerwithtimeinterval:1.0                                                target:self                                              selector:@selector(arraybuild)                                              userinfo:nil                                               repeats:yes];  }  - (void)arraybuild {      loopcount++;      // initialise array     nsmutablearray *resultsarray = [[nsmutablearray alloc]init];      if (loopcount >= 11) {          // invalidate timer         [mytimer invalidate];         mytimer = nil;          // find average         nsnumber *avg = [resultsarray valueforkeypath:@"@avg.self"];          // change text of label average & log         self.avgsignal.text = [nsstring stringwithformat:@"%@",avg];         nslog(@"%@",avg);        }else{          // declare signal strength         float signalstrength = ctgetsignalstrength();          // individual result & convert integer         nsstring *result = [nsstring stringwithformat:@"%f", signalstrength];         nsinteger resultint = [result integervalue];          // add object         [resultsarray addobject:[nsnumber numberwithfloat:resultint]];          // change text of label each second         self.avgsignal.text = [nsstring stringwithformat:@"%d",loopcount];         nslog(@"%f",signalstrength);      } } 

declare yout resultarray in .h file because each n every time you're creating new array. that's why you're not able that. please use this

.h file

nsmutablearray *resultsarray; 

.m file

- (ibaction)getsignalavg:(id)sender {      mytimer = [nstimer scheduledtimerwithtimeinterval:1.0                                                target:self                                              selector:@selector(arraybuild)                                              userinfo:nil repeats:yes];             // initialise array   if([resultarray count] == 0)     resultsarray = [[nsmutablearray alloc]init];                                     else      [resultarray removeallobjects]; }  - (void)arraybuild {      loopcount++;        if (loopcount >= 11) {          // invalidate timer         [mytimer invalidate];         mytimer = nil;          // find average         nsnumber *avg = [resultsarray valueforkeypath:@"@avg.self"];          // change text of label average & log         self.avgsignal.text = [nsstring stringwithformat:@"%@",avg];         nslog(@"%@",avg);        }else{          // declare signal strength         float signalstrength = ctgetsignalstrength();          // individual result & convert integer         nsstring *result = [nsstring stringwithformat:@"%f", signalstrength];         nsinteger resultint = [result integervalue];          // add object         [resultsarray addobject:[nsnumber numberwithfloat:resultint]];          // change text of label each second         self.avgsignal.text = [nsstring stringwithformat:@"%d",loopcount];         nslog(@"%f",signalstrength);      } }