1. 只有C#內(nèi)置類型(int,double,long等)可以聲明為const;結(jié)果、類和數(shù)組不能聲明為const。
2. readonly 是在字段上使用的修飾符,直接以類名.字段訪問(wèn)。
3. const 必須在申明中初始化。之后不能再修改。
4. readonly可以在申明中初始化,也可以在構(gòu)造函數(shù)中初始化,其它情況不能修改。
namespace const_and_readonly{class Program{static void Main(string[] args){Console.WriteLine("Half a year have {0} Moths", Calendar.Moths/2); //直接類名.字段訪問(wèn)const字段Calendar test1 = new Calendar();Console.WriteLine("Every year has {0} weeks and {1} days", test1._weeks, test1._days);//readonly字段通過(guò)實(shí)例訪問(wèn)Calendar test2 = new Calendar(31, 4);Console.WriteLine("January has {0} weeks and {1} days", test2._weeks ,test2 ._days);Console.ReadKey();}}class Calendar{public const int Moths = 12; //const必須在聲明中初始化public readonly int _days=365; //readonly在聲明中初始化public readonly int _weeks;public Calendar() //readonly在構(gòu)造函數(shù)內(nèi)初始化{_weeks = 52;}public Calendar(int days,int weeks) //readonly在構(gòu)造函數(shù)內(nèi)初始化{_days = days;_weeks = weeks;}public void setvalue(int days,int weeks){// _days = days; 無(wú)法對(duì)只讀字段賦值//_weeks = weeks; 無(wú)法對(duì)只讀字段賦值}}以上所述是小編給大家介紹的C#中const 和 readonly 修飾符的用法詳解,希望對(duì)大家有所幫助,如果大家有任何疑問(wèn)請(qǐng)給我留言,小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)VEVB武林網(wǎng)網(wǎng)站的支持!
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