diff --git a/c04_string/printout.c b/c04_string/printout.c
new file mode 100644
index 0000000..51c8a8d
--- /dev/null
+++ b/c04_string/printout.c
@@ -0,0 +1,18 @@
+/* printout.c - 使用转换说明 */
+#include <stdio.h>
+
+#define PI 3.1415927
+
+int main(void)
+{
+    int number = 7;
+    float pies = 12.75;
+    int coast = 7800;
+
+    printf("The %d contestants ate %f berry pies.\n", number, pies);
+    printf("The value of pi is %f.\n", PI);
+    printf("Farewell! thou art too dear for my possessing,\n");
+    printf("%c%d\n", '$', 2 * coast);
+    
+    return 0;
+}
\ No newline at end of file