Round down decimals javascript

Question

I am working on a JS project and i have the following problem:

My input number goes from 0 to 10. (it can be 1, 2, 3.4, 5,9, etc..)

The expected output would be something out of 5 with only one lowered down decimal.

Examples:

9.7 / 10 would give 4.85 / 5 , the output has to be 4.8 (keep only one lowered down digit)

4.9 / 10 would give 2.45 / 5, the output has to be 2.4 (keep only one lowered down digit)

Thanks for your help.

Regards

Answer 1

You can do this with a simple process:

1. Multiply your number by 10.
2. Floor it (using Math.floor).
3. Divide it by 10.

Math.floor(4.85 * 10) / 10; // 4.8
Math.floor(2.45 * 10) / 10; // 2.4
Math.floor(3 * 10) / 10;    // 3

Taking 4.85 as an example:

1. 4.85 * 10 equates to 48.5.
2. Math.floor(48.5) equates to 48.
3. 48 / 10 equates to 4.8.