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Tokens and Terms

REXX expressions and instructions may contain the following items: comment A comment is a sequence of characters (on one or more lines) delimited by /* and */. Nested comments are also valid, as /* hello /* joe */ */ string A string is a sequence of characters delimited by a single quote or double quote. Use two quotes to obtain one quote inside a string. A string may be specified in hexadecimal if the final quote is + followed by an X. If it followed by an H then is + treated as a hexadecimal number. Some valid strings are: "Marmita" 'He''s here' '2ed3'x '10'h (=16) number A number is a string of decimal digits with or without a decimal point. A number may be prefixed with a plus or minus sign, and/or written in exponential notation. Some valid numbers are: 23 12.07 141 12.2e6 +5 '-3.14' symbol A symbol refers to any group of characters from the following selection: A-Z, a-z, 0-9, @#$_.?! Symbols are always translated to uppercase. Variables are symbols but the first character must not be a digit 0-9 or a dot '.'. Each symbol may consist of up to 250 characters. function-call A function-call invokes an internal, external, or built-in routine with 0 to 10 argument strings. The called routine returns a character string. A function-call has the format: function-name( [expr][,[expr]...) function-name must be adjacent to the left parenthesis, and may be a symbol or a string. All procedures can be called as functions or procedures. If a function is called as a procedure ie. call left 'Hello',4 then the return string will be returned in the variable RESULT where is this example will contain the string 'Hell' ie. copies('ab',3) /* will return 'ababab' */ 'cd'() /* will call DOS and return current directory */

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