add

public/c/ch2/digui/printnumber.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+void printNumber2(int n)
+{
+    if (n > 9)
+    {
+        printNumber2(n / 10);
+    }
+    printf("%d", n % 10);
+}
+
+int main()
+{
+    int number = 12345; // Example number
+    printNumber2(number);
+    printf("\n"); // Newline for better output formatting
+
+    char *str = "abcde";
+    printf("%s\n", str); // 输出: abcde
+
+    char arr[] = "abcde";
+    printf("%s\n", arr); // 输出: abcde
+    return 0;
+}