1.函数指针回顾
int sum(int value1, int value2)
{
return value1 + value2;
}
int minus(int value1, int value2)
{
return value1 - value2;
}
int main(int argc, const char * argv[]) {
int (*sumP) (int, int) = sum;
int res = sumP(10, 20);
NSLog(@"res = %i", res);
int (*minusP) (int , int) = minus;
res = minusP(10, 20);
NSLog(@"res = %i", res);
return 0;
}
typedef int (*calculate) (int, int);
int main(int argc, const char * argv[]) {
calculate sumP = sum;
int res = sumP(10, 20);
NSLog(@"res = %i", res);
calculate minusP = minus;
res = minusP(10, 20);
NSLog(@"res = %i", res);
return 0;
}
2.block和typedef
int main(int argc, const char * argv[]) {
int (^sumBlock) (int, int) = ^(int value1, int value2){
return value1 + value2;
};
int res = sumBlock(10 , 20);
NSLog(@"res = %i", res);
int (^minusBlock) (int, int) = ^(int value1, int value2){
return value1 - value2;
};
res = minusBlock(10 , 20);
NSLog(@"res = %i", res);
return 0;
}
int main(int argc, const char * argv[]) {
calculateBlock sumBlock = ^(int value1, int value2){
return value1 + value2;
};
int res = sumBlock(10, 20);
NSLog(@"res = %i", res);
calculateBlock minusBlock = ^(int value1, int value2){
return value1 - value2;
};
res = minusBlock(10, 20);
NSLog(@"res = %i", res);
return 0;
}
