//指數運算

NSLog(@"%.f", pow(3,2) );//result 9

NSLog(@"%.f", pow(3,3) );//result 27

 

//開平方運算

NSLog(@"%.f", sqrt(16) );//result 4

NSLog(@"%.f", sqrt(81) );//result 9

 

//上捨入

NSLog(@"res: %.f", ceil(3.000000000001));//result 4

NSLog(@"res: %.f", ceil(3.00));//result 3

 

//下捨入

NSLog(@"res: %.f", floor(3.000000000001));//result 3

NSLog(@"res: %.f", floor(3.9999999));//result 3

floor函數：返回小於或者等於指定表達式的最大整數

 

//四捨五入

NSLog(@"res: %.f", round(3.5));//result 4

NSLog(@"res: %.f", round(3.46));//result 3

NSLog(@"res: %.f", round(-3.5));//NB: this one returns -4

 

//最小值

NSLog(@"res: %.f", fmin(5,10));//result 5

 

//最大值

NSLog(@"res: %.f", fmax(5,10));//result 10

 

//絕對值

NSLog(@"res: %.f", fabs(10));//result 10

NSLog(@"res: %.f", fabs(-10));//result 10