Why is 0.1 + 0.2 not equal to 0.3? How to solve this problem?

The internal calculation of the computer is to convert it into binary numbers, add them, and then convert them into 10 Hexadecimal number ,js Use double precision floating-point numbers to store （ Use 64 position Fixed length to save ）

0.1 and 0.2 Turn into 2 Hexadecimal followed by wireless loop 1100（ Both numbers are infinite circular decimal ）, So the sum of the two naturally does not equal 0.3 Turn into 2 The value of base

resolvent

1, Convert to integer first , Add it up and turn it back to decimal

2, Use number Object's toFixed Method ,toFixed Method can specify the number of specified digits after the decimal point of the operation result , To keep one decimal place is toFixed(1)