NSValue&NSNumber

void testForNSValue(void)

{

int i=10;

//    NSLog(@"encode(int)=%s",@encode(int));

//    NSLog(@"encode(float)=%s",@encode(float));

//    NSLog(@"encode(struct student)=%s",@encode(struct student));

NSValue* value =[[NSValue alloc]initWithBytes:&i objCType:@encode(int) ];

int ret;

[value getValue:&ret];

NSLog(@"ret=%i",ret);

struct s stt={88,99};

NSValue* value2 =[[ NSValue alloc]initWithBytes:&stt objCType:@encode(struct s)];

struct s newStt;

[value2 getValue:&newStt];

NSLog(@"newStt.a=%i, newStt.b=%i",newStt.a,newStt.b);

NSLog(@"objCType is %s", [value2 objCType]);

//    @encode(struct s) == [value2 objCType]

int *p=&i;

NSLog(@"p=%p",p);

NSValue* v3 = [[ NSValue alloc]initWithBytes:&p objCType:@encode(int *)];

int *q;

[v3 getValue:&q];

NSLog(@"q=%p",q);

}

void testNSNumber(void)

{

//对4字节有符号整型

NSNumber *obj1 = [ NSNumber numberWithInt:123];

NSLog(@"obj1 is %i",[obj1 intValue]);

//对8字节有符号整型

NSNumber *obj2 = [ NSNumber numberWithInteger:88888888];

NSLog(@"obj2 is %li", [obj2 integerValue]);

//对4字节无符号整型

NSNumber * obj3 = [ NSNumber numberWithUnsignedInt:345];

NSLog(@"obj3 is %u", [obj3 unsignedIntValue]);

//对8字节无符号整型

NSNumber* obj4 = [ NSNumber numberWithUnsignedInteger:99999999];

NSLog(@"obj4 is %lu", [obj4 unsignedIntegerValue]);

//其它的基本数据类型的封装方法

//    NSNumber numberWithUnsignedChar:<#(unsigned char)#>

//    obj4 unsignedCharValue

//    NSNumber numberWithShort:<#(short)#>

//      obj4 shortValue

//     NSNumber numberWithUnsignedLongLong:<#(unsigned long long)#>

//     obj4 unsignedLongLongValue

NSNumber* obj5 = [ NSNumber numberWithBool:YES];

NSLog(@"obj5 is %i",[obj5 boolValue]);

int a;

NSNumber * obj6 = [NSNumber numberWithUnsignedLong:(unsigned long)&a];

int * add =  (int *)[obj6 unsignedLongValue];

}