Char values, or characters, are used like this:
lda #'H' sta $0400 lda #'i' sta $0401 lda #"?!#".charAt(1) sta $0402 .byte 'H','e','l','l','o',' ' .text "World"+'!'
In the above example, chars are used in two ways. In the first examples their numeric representation are used as arguments to the lda commands and in the final example, '!'s string representation is appended to the "World" string.
Char values is a subclass of number values, which means that it has all the functions that are placed on the number values, so you can do stuff like.
lda #’H’+1 // Same as lda #’I’ sta $0400 lda #’A’+1 // Same as lda #’B’ sta $0401 lda #’L’+1 // Same as lda #’M’ sta $0402