4. CHARACTERS AND STRINGS

4.1 General Description

The character set for BASIC is contained in the ECMA 7-bit coded character set. Strings are sequences of characters and are used in BASIC programs as comments (see 19), as string constants (see 6), or as data (see 15).

4.2 Syntax

         1. letter                         = A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/S/T/U/V/W/X/Y/Z
         2. digit                          = 0/1/2/3/4/5/6/7/8/9
         3. string-character               = quotation-mark / quoted-string-character
         4. quoted-string- character       = exclamation-mark / number-sign / dollar- sign / percent-sign / ampersand /
                                             apostrophe / left-parenthesis / right- parenthesis / asterisk / comma /
                                             solidus / colon / semi-colon / less-than-sign / equals-sign / greater-than-sign /
                                             question-mark / circumflex-accent / underline / unquoted-string-character
         5. unquoted-string- character     = space / plain-string-character

4.3 Examples

        ANY CHARACTERS AT ALL (?!*!!) CAN BE USED IN A "REMARK".
        "SPACES AND COMMAS CAN OCCUR IN QUOTED STRINGS."
        COMMAS CANNOT OCCUR IN UNQUOTED STRINGS.

4.4 Semantics

The letters shall be the set of upper-case Roman letters contained in the ECMA 7-bit coded character set in positions 4/1 to 5/10. The digits shall be the set of arabic digits contained in the ECMA 7-bit coded character set in positions 3/0 to 3/9. The remaining string-characters shall correspond to the remaining graphic characters in position 2/0 to 2/15, 3/10 to 3/15 and in positions 5/14, 5/15 of the ECMA 7-bit coded character set. The names of characters are specified in Table 1. The coding of characters is specified in Table 2; however, this coding applies only when programs and/or input/output data are exchanged by means of coded media. 4.5 Exceptions None. 4.6Remarks Other characters from the ECMA 7-bit coded character set (including control characters) may be accepted by an implementation and may have a meaning to some other processor (such as an editor) but have no prescribed meaning within this Standard. Programs containing characters other than the string-characters described above are not standard-conforming programs. The several kinds of characters and strings described by the syntax correspond to the various uses of strings in a BASIC program. Remark-strings may be used in remark-statements (see 19). Quoted-strings may be used as string-constants (see 6). Unquoted-strings may be used in addition to quoted-strings as data elements (see 17) without being enclosed in quotation marks; unquoted-strings cannot contain leading or trailing spaces.