CHKCHR

Read a character from the console. * Syntax ```sbsyntax code = CHKCHR(x, y) ``` |*Input | Description | |`x`| X coordinate to read from. | |`y`| Y coordinate to read from. | |*Output | Description | |`code`| Character code read from console. | Reads the character located at (x,y) and returns a character code in range of 0-255 from the console. If attempting to read from off the edge of the screen, the return value is -1 instead. * Examples ```sb ' Set up characters to read CLS PRINT "ABC" ' will print 65 ?CHKCHR(0,0) ' will print 67 ?CHKCHR(2,0) ' will print 0 ?CHKCHR(5,5) ' will print -1 ?CHKCHR(-1,-1) ``` * Notes All arguments are rounded down. When the console has been cleared with `CLS`, the character code read from anywhere on screen will be 0. `CHKCHR` does not correctly read characters that aren't in the usual character set - if characters outside the normal range are printed, they will still return codes in the 0-255 range, but offset by 32 (0x20). For example, if using `CHKCHR` to read character 256 (character 0 of second character bank), the result would be 32. `CHKCHR` has a strange bug in which exactly one string argument can be passed and treated as a number. The empty string is treated as -1; every other string is treated as 0. ```sb ' Equivalent to CHKCHR(0,-1) ?CHKCHR(0,"") ' Causes an error ?CHKCHR("","") ``` There is no `CHKCHR` equivalent for the lower screen console. * Errors |*Action | Error | | One or zero arguments are passed | Syntax error | | Three or more arguments are passed | Missing operand | | Two string arguments are passed | Type Mismatch | * See Also - Console overview - `PRINT` - `CHR$` - `ASC`