Editing Atari BASIC (section)

==Differences from Microsoft BASIC==
*Syntax is checked and errors highlighted immediately on line entry.
*Variable names can be of arbitrary length, and all characters are significant.
*The following keywords are not in Atari BASIC: <code>INKEY$</code>, <code>CLS</code>,<code>DEF FN</code>, <code>SPC</code>, <code>TAB</code>, <code>ELSE</code>.
*All arrays must be dimensioned prior to use while Microsoft BASIC defaults an array to 10 elements if not dimensioned.
*String variables are treated as character arrays and must be dimensioned before use. MS BASIC stores strings on the [[heap (programming)|heap]] and sometimes pauses for [[Garbage collection (computer science)|garbage collection]].
*The functions <code>LEFT$</code>, <code>MID$</code>, and <code>RIGHT$</code> are replaced by string indexing.
*There is not an operator for string concatenation.
*There are no arrays of strings.
*There is no support for integer variables.
*There are no bitwise operators.
*<code>INPUT</code> does not allow a prompt.
*<code>PRINT</code> may be abbreviated as <code>?</code> as in Microsoft BASIC, but Atari BASIC does not tokenize it into <code>PRINT</code>. It remains a question mark.
*The target of <code>GOTO</code> and <code>GOSUB</code> can be a variable or expression.
*<code>RESTORE</code> may take a numeric constant, variable, or expression as a parameter, causing the next <code>READ</code> to begin from the specified line number
*<code>FOR..NEXT</code> loops in Atari BASIC must have a variable name referenced by the <code>NEXT</code> statement while Microsoft BASIC does not require it.
*Multiple variables are not permitted with <code>NEXT</code> statements as they are in Microsoft BASIC (e.g., <code>NEXT X,Y</code>).
*<code>LIST</code> uses a comma to separate a range instead of a minus sign.