李大仁博客

#if !defined(IIF)
#define IIF_IMPL(condition,true_,false_) (condition)?true_:false_
#define IIF(condition,true_,false_) IIF_IMPL(condition,true_,false_)
#endif

#if !defined(IIF) #define IIF_IMPL(condition,true_,false_) (condition)?true_:false_ #define IIF(condition,true_,false_) IIF_IMPL(condition,true_,false_) #endif

-(NSString *)decode:(NSString *)firstKey, ... NS_REQUIRES_NIL_TERMINATION
{
    va_list params; //定义一个指向个数可变的参数列表指针；
    id next;
    if (firstKey) {
        va_start(params,firstKey);//va_start  得到第一个可变参数地址,
        id key = firstKey;
        //va_arg 指向下一个参数地址
        while(key && (next = va_arg(params,id)))
        {
            if (next && key){
                if ([self isEqualToString:key]) {
                    return next;
                }
            }
            key = va_arg(params,id);
        }
        return key;
        //置空
        va_end(params);
    }else{
        return firstKey;
    }
}

-(NSString *)decode:(NSString *)firstKey, ... NS_REQUIRES_NIL_TERMINATION { va_list params; //定义一个指向个数可变的参数列表指针； id next; if (firstKey) { va_start(params,firstKey);//va_start 得到第一个可变参数地址, id key = firstKey; //va_arg 指向下一个参数地址 while(key && (next = va_arg(params,id))) { if (next && key){ if ([self isEqualToString:key]) { return next; } } key = va_arg(params,id); } return key; //置空 va_end(params); }else{ return firstKey; } }

    //IIF使用DEMO
    int a = 1;
    //单次
    NSString *result1 = IIF(a==1, @"a = 1", @"a <> 1");
    //级连
    NSString *result2 = IIF(a==1, IIF(a==2, @"a = 2", @"a <> 2"), @"a <> 1");
    //DECODE使用DEMO
    NSString *str2Decode = @"abc";
    //支持使用Default
    NSString *decodeResult1 = [str2Decode decode:@"key1",@"1",@"abc",@"2",@"efg",@"3",@"with default",nil];
    //不使用Default
    NSString *decodeResult2 = [str2Decode decode:@"key1",@"1",@"abc",@"2",@"efg",@"3",nil];

//IIF使用DEMO int a = 1; //单次 NSString *result1 = IIF(a==1, @"a = 1", @"a <> 1"); //级连 NSString *result2 = IIF(a==1, IIF(a==2, @"a = 2", @"a <> 2"), @"a <> 1"); //DECODE使用DEMO NSString *str2Decode = @"abc"; //支持使用Default NSString *decodeResult1 = [str2Decode decode:@"key1",@"1",@"abc",@"2",@"efg",@"3",@"with default",nil]; //不使用Default NSString *decodeResult2 = [str2Decode decode:@"key1",@"1",@"abc",@"2",@"efg",@"3",nil];