The integer value of a space is ' '. A char (as denoted by the single quotes) is an integer value.
The ASCII value of ' ' happens to be 32, but that's harder to remember and recognize in the code. Also, you might be working in hex values, in which case the value is 0x20. And someday you might work on a system that doesn't use ASCII, and then the space character might not be 32. If you want to use the value of the space, then use the space character itself.