FreeBasic Input Keyword

last modified June 16, 2025

The FreeBasic Input keyword is used to read user input from the console. It pauses program execution and waits for the user to enter data followed by the Enter key.

Basic Definition

In FreeBasic, Input is a statement that reads data from the standard input (keyboard). It can read numeric values, strings, or multiple values in one statement.

The Input statement is essential for interactive console applications. It allows programs to receive dynamic input from users during runtime.

Basic String Input

This example demonstrates how to read a simple string input from the user.

input_string.bas

Dim fname As String

Print "Enter your name: ";
Input fname

Print "Hello, "; fname; "!"

Here we declare a string variable and use Input to read user input. The semicolon after the prompt keeps the cursor on the same line. The entered text is stored in the fname variable.

Numeric Input

The Input statement can also read numeric values directly.

input_numeric.bas

Dim age As Integer

Print "Enter your age: ";
Input age

Print "In 10 years you will be "; age + 10

This example reads an integer value from the user. FreeBasic automatically converts the input string to the numeric type. If non-numeric input is entered, a runtime error will occur.

Multiple Input Values

Input can read multiple values separated by commas in one statement.

input_multiple.bas

Dim x As Integer, y As Integer

Print "Enter two numbers separated by comma: ";
Input x, y

Print "Sum: "; x + y
Print "Product: "; x * y

This code reads two integers at once. The user must separate values with commas. The input is automatically split and assigned to the variables in order. Extra values are ignored.

Input with Prompt Message

The Input statement can include an optional prompt message.

input_prompt.bas

Dim color As String

Input "What is your favorite color? ", color

Print "Nice choice! "; color; " is a beautiful color."

Here the prompt message is part of the Input statement. This is more concise than separate Print and Input statements. The comma after the prompt adds a question mark and space.

Input with Line Input

For reading entire lines including commas, use Line Input.

input_line.bas

Dim address As String

Print "Enter your full address: ";
Line Input address

Print "Your address is: "; address

Line Input reads the entire line until Enter is pressed, including commas. This is useful when you need to read text that might contain delimiter characters.

Input with Validation

This example shows how to validate numeric input using a loop.

input_validation.bas

Dim number As Integer
Dim valid As Boolean = False

While Not valid
    Print "Enter a number between 1 and 100: ";
    Input number
    
    If number >= 1 And number <= 100 Then
        valid = True
    Else
        Print "Invalid input. Try again."
    End If
Wend

Print "You entered: "; number

This code repeatedly asks for input until a valid number is entered. The While loop continues until the valid flag is set to true. This pattern is common for robust input handling.

Input with Default Value

Here's how to implement input with a default value that can be overridden.

input_default.bas

Dim filename As String = "default.txt"
Dim temp As String

Print "Enter filename (default: "; filename; "): ";
Line Input temp

If Len(temp) > 0 Then
    filename = temp
End If

Print "Using file: "; filename

This example shows a filename input with a default value. If the user just presses Enter, the default is used. Otherwise, the input value is stored. The Len function checks for empty input.

Best Practices

Validation: Always validate user input to prevent errors.
Prompts: Make input prompts clear and descriptive.
Defaults: Provide default values when appropriate.
Types: Use the correct variable type for expected input.
Error Handling: Consider using error handling for numeric input.

This tutorial covered the FreeBasic Input keyword with practical examples showing its usage in different scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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