How to Reliably Format Numbers to Always Show Two Decimal Places?

How to Format Numbers to Always Show 2 Decimal Places

Objective:

The goal is to consistently display numbers with two decimal places, rounding them as necessary.

Example:

number	display
1	1.00
1.341	1.34
1.345	1.35

Initial Approach:

Using parseFloat(num).toFixed(2); to format numbers has been unsuccessful, as it displays values like 1 without the desired decimal.

Solution:

To achieve the desired formatting, use the following formula:

(Math.round(num * 100) / 100).toFixed(2);

Explanation:

This solution involves three key steps:

1. Multiply by 100: This step shifts the decimal point two places to the right, allowing for precise rounding without losing any significant digits.
2. Round the result: Math.round() is applied to round the value to the nearest integer.
3. Divide by 100: This step brings the decimal point back to its original position, ensuring that the number is displayed with exactly two decimal places.

Code Demonstration:

var num1 = "1";
document.getElementById('num1').innerHTML = (Math.round(num1 * 100) / 100).toFixed(2);

var num2 = "1.341";
document.getElementById('num2').innerHTML = (Math.round(num2 * 100) / 100).toFixed(2);

var num3 = "1.345";
document.getElementById('num3').innerHTML = (Math.round(num3 * 100) / 100).toFixed(2);

Output:

number	display
1	1.00
1.341	1.34
1.345	1.35

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