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标题: NSNumber [打印本页]

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作者: yanggangcl    时间: 2015-11-4 22:43
标题: NSNumber
NSNumber可以用来代表C语言的任何基础数据类型，如int, double, char, float, long, short，及其被unsigned修饰时的各类型，以及OC中的BOOL型。
1，基础数据类型 ------> NSNumber :

1. NSNumber *magicNumber = [[NSNumber alloc] initWithInt:42];
   
2. NSNumber *unsignedNumber = [[NSNumber alloc] initWithUnsignedInt:42u];
   
3. NSNumber *longNumber = [[NSNumber alloc] initWithLong:42l];
   
4. NSNumber *boolNumber = [[NSNumber alloc] initWithBOOL:YES];
   
5. NSNumber *simpleFloat = [NSNumber numberWithFloat:3.14f];
   
6. NSNumber *betterDouble = [NSNumber numberWithDouble:3.1415926535];
   
7. NSNumber *someChar = [NSNumber numberWithChar:'T'];
   

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及其简便版：

1. NSNumber *magicNumber = @42;
   
2. NSNumber *unsignedNumber = @42u;
   
3. NSNumber *longNumber = @42l;
   
4. NSNumber *boolNumber = @YES;
   
5. NSNumber *simpleFloat = @3.14f;
   
6. NSNumber *betterDouble = @3.1415926535;
   
7. NSNumber *someChar = @'T';
   

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2，NSNumber  -----> 基础数据类型
int scalarMagic = [magicNumber intValue];
unsigned int scalarUnsigned = [unsignedNumber unsignedIntValue];
long scalarLong = [longNumber longValue];
BOOL scalarBool = [boolNumber boolValue];
float scalarSimpleFloat = [simpleFloat floatValue];
double scalarBetterDouble = [betterDouble doubleValue];
char scalarChar = [someChar charValue];

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