How to use javascript to get float decimal digits _ javascript tips-js tutorial

In js, the most common method for getting the decimal point and the two decimal points is the rounding function. I have previously introduced this common function in js, which is useful here, next, let's take a look at some methods to get the float decimal point and sum up the following: we will introduce the implementation of JavaScript to retain two decimal places:
Rounding
The following processing results are rounded up:

Var num = 2.446242342; num = num. toFixed (2); // The output result is 2.45.

Rounding
The following processing results are not rounded up:
First, add the decimal side integer:

Math. floor (15.7784514000*100)/100 // The output result is 15.77.

Second, use regular expression matching as a string:

Number (15.7784514000.toString (). match (/^ \ d + (? : \. \ D {0, 2 })? //) // The output result is 15.77, which cannot be used as an integer. For example, 10 must be written as 10.0000.

NOTE: If it is a negative number, convert it to a positive number before calculation, and then convert it back to a negative number.

Example of javascript retaining two decimal places: