java-scientific-calculator

A Java calculator with standard operations

Java Scientific Calculator (Swing)

A desktop calculator built with Java Swing (NetBeans GUI) that supports standard arithmetic plus a few scientific functions, with smart output formatting and guardrails.

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Features

• Arithmetic: +, −, ×, ÷
• Scientific:
  • x² (square)
  • √x (square root)
  • π×x (multiply current value by π)
• Input & Display UX:
  • Sign toggle +/−
  • Decimal guard (prevents multiple .)
  • Backspace <, C (clear entry), AC (full reset)
  • Output formatting:
    • Trims trailing .0 (e.g., 12.0 → 12)
    • Caps display length to 10 characters while preserving scientific notation (e.g., 1.23E9)
• Chaining: Pressing an operator stores the current number; selecting another operator applies the previous one (sequential evaluation).
• Polish: Prevents editing a finalized answer until new input; friendly warnings; a tiny easter egg button (“Don’t Push”).

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How It Works

• Main class: finalproject.FormB (JFrame with right-aligned JTextField display and button grid)
• State variables:
  • input1, input2, outcome
  • Operation flags: mul, div, add, sub
  • ansDisplay (locks display after =), limit (max input length), curOP (op sequence counter)
• Core methods:
  • operate() — executes + / − / × / ÷ on input1 and input2
  • extraOP(int) — applies x², √x, π×x immediately to current display
  • cutzero() & cutLimit() — trims trailing .0 and enforces 10-char display, respecting scientific notation
  • typeNumber(String) / delete() — controlled input & backspace behavior

Operator precedence is sequential (in the order you press buttons), not algebraic precedence.

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