parseInt() & radix basics

Question

Can someone please explain what radix is (on the most fundamental level), in reference to parseInt()?

I'm also not understanding how the string argument changes with different bases/radix.

Answer 1

Regardless of the language you are using, here is an attempt at a general explanation:

The radix is the base of a numeral system.

Decimal system: radix is 10, therefore 100₁₀ means 100.

Binary system: radix is 2, therefore 100₂ means 4.

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This is why parseInt(number, radix) needs to know the radix you are working with, so that

parseInt(100, 2)

correctly yields 4 if you're in binary and

parseInt(100, 10)

correctly yields 100 in decimal.

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Recommended Reading: Number Systems and Bases