Programming Fundamentals

INPUT is designed for interactive data entry where values change frequently. PRINT only outputs, LET assigns fixed values, and PROMPT is not a standard BASIC statement.

When the user enters incorrect data type in BASIC INPUT (e.g., text when number expected), the message 'Redo from start' prompts re-entry from the beginning.

SELECT CASE and both single-alternative and double-alternative block IF statements are all control structures that direct program flow. END is a termination keyword used to close blocks, but it doesn't control program flow itself. END simply marks the conclusion of a block structure like IF or SELECT CASE.

Control statements like IF, SELECT CASE, and loops allow programmers to alter the sequential execution of a program. Inquiry-and-response handles user input, Print displays output, and Flowcharting is a design tool. Only control statements actively change the flow of program execution by making decisions or repeating actions based on conditions.

In block IF structures, the block must be properly terminated. The END IF statement marks the conclusion of the IF block. While END alone terminates other structures like SELECT CASE, the specific syntax for block IF requires END IF to properly close the conditional block and maintain code clarity.

Non-executable statements like REM (remark/comment) are ignored during program execution. When a non-executable statement appears after a block IF, the program simply skips it and continues to the next executable statement. The block IF has already been evaluated, and execution proceeds to the first executable instruction following the REM statement. No error occurs, and the IF is not re-executed.

A menu is a user interface element that displays a list of available program functions or options. Users select one item from the menu to invoke that specific function. Collating sequences determine character ordering, boolean operators combine logical conditions, and relational operators compare values - none of these display selectable function lists.

In a double-alternative block IF, the condition is evaluated once. If true, the THEN clause executes and the ELSE clause is skipped. If false, the ELSE clause executes and the THEN clause is skipped. Only one of the two clauses ever executes during a single pass through the IF statement - never both, and never neither.

The CLS (Clear Screen) command is used to clear the output screen in BASIC programming. This removes any previous text or output, providing a clean slate for displaying new program results. It's especially useful when you want fresh, uncluttered output for the user.

In an IF-THEN-ELSE structure, when the condition evaluates to true, only the THEN clause is executed. The ELSE clause is skipped entirely.

A variable is a named storage location that holds values which can be modified during program execution. Unlike constants, variables allow programs to work with changing data. This fundamental concept enables dynamic programming and data manipulation.

Concatenation is the operation of joining two or more strings end-to-end to create a single combined string. This is a fundamental string operation in programming, used extensively in text processing, formatting output, and building file paths. The term comes from Latin meaning 'to link together'.

Option (2) is correct.

The CURSOR_ALREADY_OPEN exception is thrown when we are trying to open a cursor that is already open. A cursor cannot be opened twice without closing it first.