Cocoa Programming Tips 1001
Foundation
NSNumber
Foundation - NSNumber
組み込み型を NSString で取り出す
Keywords: objCType
NSNumber は C の組み込み型をラップするためのクラス。その、ラップ元の型を NSString として取り出す関数を作ってみよう。もとの型は objCType で取り出すことができる。取り出した文字列を @encode() したものと比べるんだ。
(sample)
NSString* stringOfNumber(NSNumber* number)
{
static NSString* _b = @"BOOL";
static NSString* _c = @"char";
static NSString* _s = @"short";
static NSString* _i = @"int";
static NSString* _l = @"long";
static NSString* _ll = @"long long";
static NSString* _f = @"float";
static NSString* _d = @"double";
static NSString* _uc = @"unsigned char";
static NSString* _us = @"unsigned short";
static NSString* _ui = @"unsigned int";
static NSString* _ul = @"unsigned long";
static NSString* _ull = @"unsigned long long";
const char* type;
// Get Objective-C type
type = [number objCType];
if (strcmp(type, @encode(BOOL)) == 0) return _b;
if (strcmp(type, @encode(char)) == 0) return _c;
if (strcmp(type, @encode(short)) == 0) return _s;
if (strcmp(type, @encode(int)) == 0) return _i;
if (strcmp(type, @encode(long)) == 0) return _l;
if (strcmp(type, @encode(long long)) == 0) return _ll;
if (strcmp(type, @encode(float)) == 0) return _f;
if (strcmp(type, @encode(double)) == 0) return _d;
if (strcmp(type, @encode(unsigned char)) == 0) return _uc;
if (strcmp(type, @encode(unsigned short)) == 0) return _us;
if (strcmp(type, @encode(unsigned int)) == 0) return _ui;
if (strcmp(type, @encode(unsigned long)) == 0) return _ul;
if (strcmp(type, @encode(unsigned long long)) == 0) return _ull;
}これで組み込み型が読みやすい形で取り出せるぜ！