Syntax errors are shown in the error messages window (at the bottom of the RBASIC IDE window), if the program is not syntactically correct. The syntax error message also contains the location (line and column) of the error. If you double-click on the error message, the cursor jumps to the location of the error.

Summary of errors and their explanation:

Error 1: Command expected here

A command is expected at the beginning of the line, immediately after a colon and after THEN or ELSE commands.

Error 2: ')' missing

Too many arguments in a parameter list, or missing parenthesis in an arithmetic expression.

Error 3: Illegal number

Not a valid floating point number (in decimal system).

Error 4: Unexpected end of line

End of the command line was encountered while the last command has not been completed.

Error 5: '(' expected here

A parameter list is expected after the function (or command) identifier.

Error 6: Unterminated string

Starting quote begins the string, but the ending one is not found.

Error 7: ']' is missing

Missing bracket behind the index list (in an array element).

Error 8: Numeric expression expected here

Numeric operand expected.

Error 9: String expression expected here

String operand expected.

Error 10: ':' expected here

A symbol other than ':' was found after a command.

Error 11: '=' expected here

The assignment sign was expected after a variable in the FOR or LET commands.

Error 12: Identifier expected here

A variable, or a function expected.

Error 13: 'TO' statement expected here

Incomplete FOR command.

Error 14: 'THEN' statement expected here

Incomplete THEN command.

Error 15: ',' expected here

Incorrect argument list (too few arguments).

Error 16: ELSE without IF

ELSE without IF found.

Error 17: Reserved variable

Attempt to write to an read-only variable (RND,DATE$,TIME$...).

Error 18: Unknown label

Identifier used in the GOTO, or GOSUB command has not been declared as a label.

Error 19: Using SQRT with negative argument

Attempt to calculate a square root of a negative value.

Error 20: Undefined array

Attempt to access an element of an undefined array.

Error 21: Array too large

Attempt to define an array with more than a million elements.

Error 22: Not enough memory

Not enough memory to allocate for a defined array.

Error 23: Index out of range

One of array element indexes is bigger than the defined array dimension.

Error 24: RETURN without GOSUB

Using RETURN without previous use of GOSUB.

Error 25: Stack overflow

Stack size reached 100000 items.

Error 26: NEXT without FOR

Using NEXT with a variable, which is not used in the FOR loop.

Error 27: FOR without NEXT

FOR command defines the loop, which has to immediatelly end, but its NEXT statement is not found.

Error 28: Division by zero

Zero is the divisor in an expression.

Error 29: Invalid argument

The function cannot process such argument.

Error 30: Graphics is not opened

OPENGRAPH command failed.

Error 31: Unknown graph

Attempt to use an unopened graphic window.

Error 32: Floating point error

Error in a mathematical operation (invalid argument in a function).

Error 33: Cannot open the file

File not found.

Error 34: File not opened

Attempt to use a file which has not been opened.

Error 35: Unable to write to file

Write to file failed (disk full?).

Error 36: Unable to remove a file

REMOVEFILE failed (file is locked).

Error 37: Floating point overflow

Using number greater than 10^300.

Error 38: Receiver returned error

An error occured while controlling the receiver.