Decimal home approximation in Javascript

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8

What is the reason for the behavior below? Why not give 3.3?

I am running Javascript in the console and is returning this result. 

Number(1.1)
1.1

Number(1.1) + Number(1.1)
2.2

Number(1.1) + Number(1.1) + Number(1.1)
3.3000000000000003

Number(1.1) + Number(1.1) + Number(1.1) + Number(1.1)
4.4

Number(1.1) + Number(1.1) + Number(1.1) + Number(1.1) + Number(1.1)
5.5
javascript

  • What behavior?

  • The 3.3 trillion trillion instead of 3.3... @Miguelneto

2 answers

3

This is due to floating-point accuracy errors, since it is not possible to map 1.1 to a finite binary value. A similar issue can be seen here.
This behavior can be changed through the toFixed function().
Example:

(1.1 + 1.1 + 1.1).toFixed(2)

2 being the number of decimal places.

2

Number is a javascript function that converts the string to a floating point value Note that within parentheses there is .(dot), then the string within parentheses is converted to floating point.

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