%d is an integer decimal and %c is a character type. There are also some commonly used formats %s, %f, %x, how to check them yourself? They just output in different formats. If it is printf("%d, %d ",ch 1, CH2);

Then 67, 68; If it is printf("%c, %c ",ch 1, ch2), the output is c, d; Please refer to /link for details? URL = epmlewfczi 80 tdhxu 2 altv 3 wf 3 cmxlqtfxcimgcx 1YY _ et 8 ozgsahsn 1 idddroczuy 26d 12mq 8-tutdxonhbl s4r 1 zdgvmdts 3 fsbr l5 xs