Why 0.1 + 0.2 = 0.30000000000000004 (in Javascript)?

Question

0.1 + 0.2 = 0.3, but in Javascript 0.30000000000000004. Why?

Answer 1

Computer can't store floating point too accurately. Use toFixed to set it to less decimal point.

In equelity comparison, never apply strict equality to floating point "===", use equality "==" and adjust toFixed function instead.

console.log((0.1+ 0.2)===0.3? "true":"false"); // return false
console.log((0.1+ 0.2).toFixed(16)==0.3? "true":"false"); // return true