Decimal numbers

A decimal number has a fraction part: ၃.၁၄, ၀.၅, -၂.၅. Its kind is ဒဿမကိန်း ("decimal number"). Other languages call these floating-point numbers, or floats.

၃.၁၄ ကို ပြသပါ။                    // a decimal point makes a decimal number
-၂.၅ ကို ပြသပါ။
ဒဿမကိန်း ၁၀ ကို ပြသပါ။             // the kind prefix makes 10 a decimal number
1.5e3 ကို ပြသပါ။                   // scientific notation: 1.5 × 10³
1.5e-3 ကို ပြသပါ။                  // 1.5 × 10⁻³
၇.၀ / ၂ ကို ပြသပါ။                  // decimal division keeps the fraction

၃.၁၄
-၂.၅
၁၀.၀
၁၅၀၀.၀
၀.၀၀၁၅
၃.၅

A decimal number prints with a decimal point each time, even when it is a whole number (၁၀.၀).

Sizes

Like integers, decimal numbers come in sizes. More bits mean more correct digits.

Kind	Bits	Correct digits (about)
၁၆ ဘစ် ဒဿမကိန်း	16	3
၃၂ ဘစ် ဒဿမကိန်း	32	7
ဒဿမကိန်း, ၆၄ ဘစ် ဒဿမကိန်း	64	15 (the default)
၁၂၈ ဘစ် ဒဿမကိန်း	128	33

Close, not exact

Decimal numbers are stored in base 2, so most fractions are stored as a close neighbour and not as the true value. Most of the time this goes unnoticed, but now and then the last digits show it:

၀.၁ + ၀.၂ ကို ပြသပါ။
၁၆ ဘစ် ဒဿမကိန်း ၀.၁ ကို ပြသပါ။    // fewer bits, a less close neighbour

၀.၃၀၀၀၀၀၀၀၀၀၀၀၀၀၀၀၄
၀.၀၉၉၉၇၆

This is true of decimal numbers in almost all programming languages, not just Zaka.

Rules

• Decimal numbers are written in base 10 and no other base.
• Scientific notation (e3, E-3) needs Western digits: 1.5e3, not ၁.၅e3.

Hands on

• Print ၁ / ၃ and then ၁.၀ / ၃. What is different?
• Print ၃၂ ဘစ် ဒဿမကိန်း ၀.၁. Is it closer to 0.1 than the 16-bit one?

Next: Characters.