C#中有關字符串的一些方法

利用C#,不調用系統提供的庫函數的情況下,編寫出幾個有關字符串的操作方法:

namespace StringOperate
{
    class StrOperate
    {
        //return a copy of the src
        public static char[] StrCopy(char[] src)
        {
            char[] data = null;
            if (ReferenceEquals(src, null))
            {
                return data;
            }

            int length = src.Length;
            data = new char[length];
            for (int i = 0; i < length; i++)
            {
                data[i] = src[i];
            }

            return data;
        }

        //copy the src to the des and return the des
        public static char[] StrCopy(out char[] des, char[] src)
        {
            if (ReferenceEquals(src, null))
            {
                des = null;
                return des;
            }