Check Capture and Check Processing: Appendix

What is NULL? How is it defined, and where? How is it used? Character Processing. 1.) Understand the difference between characters and integers, and the concept of ASCII values. For example, what does it mean if someone types: 'x' - 'a'. Similarly, how is the integer 1 different from the character '1'? What is the difference between using %c ... ................
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