Ghostline Labs Academic Archive

JavaScript Calculator

An updated version of an early extra-credit web development project.

The calculator demonstrates JavaScript event handling, DOM manipulation, arithmetic processing, responsive interface design, keyboard input, and light-and-dark theme support.

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Archived Project JavaScript DOM Events Responsive UI

Ghostline Labs

Basic Calculator

Ready
 

Keyboard supported: numbers, decimal, operators, Enter, Backspace, and Escape.

Project Overview

A small project with useful programming lessons.

The original calculator was created as an extra-credit assignment. This updated edition preserves the original purpose while improving its structure, accessibility, safety, and presentation.

DOM

Event Handling

Calculator buttons use JavaScript event listeners instead of inline HTML event attributes.

LOGIC

Arithmetic Processing

Expressions are parsed and calculated without relying on JavaScript’s eval() function.

UI

Responsive Interface

The calculator adapts to desktop and mobile screens while preserving clear controls and readable output.

Modernized Archive

Updated without hiding the project’s academic origin.

This remains a learning project rather than a commercial Ghostline product.

The redesign gives the project a place within the Ghostline Labs archive while preserving it as an example of early JavaScript development.

Improvements in This Version

  • Shared Ghostline navigation and footer
  • Light Mode as the default appearance
  • Working sitewide theme preference
  • Accessible button labels
  • Keyboard input support
  • Backspace and clear controls
  • Operator-precedence calculations
  • Division-by-zero error handling
  • No inline JavaScript handlers
  • No use of eval()