Question 1

What expressions can I evaluate?

Accepted Answer

This tool evaluates standard JavaScript math expressions: arithmetic (+, -, *, /), exponentiation (**), modulo (%), Math functions (Math.sqrt, Math.pow, Math.sin, Math.log, etc.), and parentheses for grouping.

Question 2

Is this safe to use for sensitive calculations?

Accepted Answer

Yes for math. This tool evaluates expressions client-side using a sandboxed parser — it does not execute arbitrary code. Floating-point precision limitations of IEEE 754 (JavaScript's number type) apply: 0.1 + 0.2 may return 0.30000000000000004.

Question 3

Why does 0.1 + 0.2 not equal 0.3 exactly?

Accepted Answer

JavaScript (and most programming languages) uses 64-bit floating-point (IEEE 754) arithmetic. Some decimal fractions cannot be represented exactly in binary. This is a fundamental property of floating-point math, not a bug. Use toFixed(2) for display purposes when needed.

JS数学计算器

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