JavaScript Number toFixed() Method
JavaScript is a high-level programming language that is used to create interactive web pages and applications. One of the most useful methods in JavaScript is the Number toFixed() method.
In this article, we’ll explore what this method does, its parameters, and how to use it in different scenarios.Have you ever encountered a number with too many digits after the decimal point, making it hard to read and use? Or maybe you needed to represent a number with a fixed number of decimal points, without any trailing digits.
This is exactly what the Number toFixed() method does. It’s a method that can be used to format a number with a specific number of decimal points.
Example 1: Remove decimal part from numbers
Let’s say that you have a number like 3.14159265359, and you want to remove the decimal part from it. With the toFixed() method, you can achieve this by invoking the method with a parameter of 0.
const pi = 3.14159265359;
const integerPart = pi.toFixed(0);
console.log(integerPart); // 3
In this example, the toFixed() method removes the decimal part of the number, thus returning only the integer part. Example 2: Round number to fixed decimal point
In some cases, you might want to round a number to a specific number of decimal points.
You can achieve this by invoking the toFixed() method with a parameter that specifies the number of decimal points to round to. const number = 3.14159265359;
const roundedNumber = number.toFixed(2);
console.log(roundedNumber); // 3.14
In this example, we’re rounding the number to two decimal points by invoking the toFixed() method with a parameter of 2.
Example 3: Add padding to decimal digits
Sometimes you might need to add padding to a number’s decimal digits to make it easier to read. You can do this by invoking the toFixed() method with a parameter that specifies the number of decimal points to add padding to.
const number = 3.14;
const paddedNumber = number.toFixed(5);
console.log(paddedNumber); // 3.14000
In this example, the toFixed() method adds padding to the decimal digits of the number, adding zeroes until it has a total of five decimal points. Example 4: Round number represented via exponential notation
Numbers that have a large or small magnitude are often represented using exponential notation.
If you want to round a number represented in exponential notation, you can do so by invoking the toFixed() method with a parameter that specifies the number of decimal points to round to. const number = 1.23e+5;
const roundedNumber = number.toFixed(2);
console.log(roundedNumber); // 123000.00
In this example, we’re rounding a number represented in exponential notation to two decimal points by invoking the toFixed() method with a parameter of 2.
Exceptions
The toFixed() method can only be applied to numeric values; if you try to apply it to non-numeric values, a TypeError is thrown. Example 5: Use method with non-numeric values
If you try to apply the toFixed() method to a non-numeric value, you’ll get an error message.
const notANumber = “Hello”;
const error = notANumber.toFixed(2);
// Uncaught TypeError: notANumber.toFixed is not a function
In this example, we’re trying to use the toFixed() method with a non-numeric value, which causes a TypeError to be thrown. Parameters of
JavaScript Number toFixed() Method
The toFixed() method takes one parameter: the number of decimal points to round to.
This parameter is optional, and if not specified, the method will return the number as is, without any rounding.
decimals parameter
The
decimals parameter specifies the number of decimal points to round the number to. If this parameter is not specified, the method will return the number as is, without any rounding.
Conclusion
In this article, we explored the JavaScript Number toFixed() method and its parameters. We saw examples of how to use it to remove the decimal part from a number, round a number to a fixed number of decimal points, and add padding to a number’s decimal digits.
We also saw an example of an error that can be thrown when trying to use the method with a non-numeric value. Knowing how to use the toFixed() method can make your JavaScript code more efficient and easier to read.
3) Example 1: Use the number.toFixed() Method to Remove Decimal Part From Numbers
The Number toFixed() method is a powerful tool in JavaScript that allows you to format a number by removing, rounding, or padding the decimal digits. In this section, we’ll see how to use this method to remove the decimal part of a number.
Default value of decimals
By default, if you don’t specify a value for the
decimals parameter in the toFixed() method, it will round the number to zero decimal points. Let’s see an example:
const number = 3.14159265359;
const roundedNumber = number.toFixed();
console.log(roundedNumber); // 3
In this example, we’re invoking the toFixed() method on a number with several decimal points.
Since we didn’t specify any value for the
decimals parameter, the method defaulted to zero decimal points, effectively removing the decimal part of the number. If we wanted to remove the decimal part of a number while preserving the integer value, we could set the value of the
decimals parameter to zero, like this:
const number = 4.5;
const integerPart = number.toFixed(0);
console.log(integerPart); // 4
Here, we’re using the toFixed() method to remove the decimal part of a number.
However, instead of defaulting to zero decimal points, we’re explicitly setting the value of the
decimals parameter to zero. This ensures that the method only returns the integer part of the number.
4) Example 2: Use the number.toFixed() Method to Round the Number to a Fixed Decimals Point
In this section, we’ll explore how to use the Number toFixed() method to round a number to a fixed number of decimal points. Using
decimals parameter
To round a number to a fixed number of decimal points, you can specify the number of decimal points you want to round to using the
decimals parameter in the toFixed() method.
Let’s see an example:
const number = 3.14159265359;
const roundedNumber = number.toFixed(2);
console.log(roundedNumber); // 3.14
Here, we’re using the toFixed() method to round a number to two decimal points. We’re specifying the value of the
decimals parameter as 2, to indicate that we want the number rounded to two decimal points.
If we wanted to round to a single decimal point, we could set the value of the
decimals parameter to one, like this:
const number = 4.567;
const roundedNumber = number.toFixed(1);
console.log(roundedNumber); // 4.6
In this example, we’re rounding a number to a single decimal point. We’re specifying the value of the
decimals parameter as 1, to indicate that we want the number rounded to one decimal point.
Conclusion
In this article, we’ve covered two examples of how to use the Number toFixed() method in JavaScript. We’ve seen how to use this method to remove the decimal part of a number, and how to round a number to a fixed number of decimal points.
By leveraging the toFixed() method, you can format numbers in your JavaScript code to make them easier to read, use, and manipulate. 5) Example 3: Use the number.toFixed() Method to Add Padding to Decimal Digits
In this section, we’ll explore how to use the Number toFixed() method to add padding to decimal digits.
Adding padding to decimals
To add padding to the decimal digits of a number, you can specify the number of decimal points you want to add using the
decimals parameter in the toFixed() method. Let’s see an example:
const number = 3.14;
const paddedNumber = number.toFixed(5);
console.log(paddedNumber); // 3.14000
Here, we’re using the toFixed() method to add padding to the decimal digits of a number.
We’re specifying the value of the
decimals parameter as 5, to indicate that we want five decimal points. This ensures that the decimal digits of the number are padded with zeroes.
You can also use this method for numbers that have fewer decimal points than the specified number of decimal points:
const number = 3.14159;
const paddedNumber = number.toFixed(7);
console.log(paddedNumber); // 3.1415900
In this example, we’re adding padding to a number that has fewer than seven decimal points. However, since we specified seven decimal points in the
decimals parameter, the toFixed() method padded the digits with zeroes until the total number of decimal points reached seven.
6) Example 4: Use the number.toFixed() Method to Round the Number Represented via Exponential Notation
In this section, we’ll explore how to use the Number toFixed() method to round a number represented in exponential notation.
Rounding exponential numbers
If you’re working with numbers that have a large or small magnitude, they are often represented using exponential notation. The Number toFixed() method can be used to round a number represented in exponential notation to a fixed number of decimal points.
const number = 1.23e+5;
const roundedNumber = number.toFixed(2);
console.log(roundedNumber); // 123000.00
In this example, we’re rounding a number represented in exponential notation to two decimal points. We’re using the toFixed() method and specifying the value of the
decimals parameter as 2, which rounds the number to two decimal points.
The toFixed() method is particularly useful for working with numbers of large magnitude that are difficult to read or manipulate. By rounding these numbers to a fixed number of decimal points, you can make them easier to work with and more accessible to other programmers.
Conclusion
In this expanded article, we covered two additional examples of how to use the Number toFixed() method in JavaScript. We’ve seen how to use this method to add padding to decimal digits and how to round numbers represented in exponential notation.
By using the toFixed() method, you can customize the format of your numbers in your JavaScript code to make them more legible and easier to work with. 7)
Exceptions
When working with the Number toFixed() method in JavaScript, it’s important to be aware of the exceptions that can arise.
One of the most common exceptions is a TypeError that occurs when trying to use the method with non-numeric values.
TypeError with non-numeric values
The Number toFixed() method is designed to work on numeric values only. If you attempt to use it with non-numeric values, a TypeError will be thrown.
Let’s see an example:
const string = ‘Hello’;
const result = string.toFixed(2);
console.log(result); // Uncaught TypeError: string.toFixed is not a function
In this example, we’re attempting to use the toFixed() method with a non-numeric string value. The method throws a TypeError because it can’t operate on non-numeric values.
To avoid this error, you should always ensure that the input is of the correct data type before invoking the toFixed() method. One possible way to check whether a value is numerical or not is to use the isNaN() function:
const value = ‘3.14’;
if (!isNaN(value)) {
const result = Number(value).toFixed(2);
console.log(result); // 3.14
}
In this example, we’re using the isNaN() function to check whether a value is numeric or not.
If the value is numeric, we then use the Number() method to convert the value to a number before using the toFixed() method. 8) Example 5: Use the number.toFixed() Method With Non-Numeric Values
Although the toFixed() method is designed to work on numerical values, it’s possible to use it with non-numeric values under certain circumstances.
Using method with non-numeric values
If you have a non-numeric value that can be converted to a number, you can still use the toFixed() method on it. One way to do this is to first convert the value to a number using the Number() method.
const value = ‘3.14’;
const result = Number(value).toFixed(2);
console.log(result); // 3.14
In this example, we’re using the Number() method to convert the string value to a number before applying the toFixed() method. This allows us to use the toFixed() method on a non-numeric value.
However, it’s important to note that this approach only works for non-numeric values that can be converted to a number. If the value cannot be converted to a number, a TypeError will still be thrown.
Conclusion
In this expanded article, we covered two important topics related to the Number toFixed() method in JavaScript. We’ve seen how to handle exceptions such as TypeErrors that can be thrown when using the method with non-numeric values.
We also explored how to use the toFixed() method with non-numeric values under certain circumstances by converting the value to a number. By being aware of these exceptions and approaches, you can use the toFixed() method more effectively and avoid runtime errors in your JavaScript code.
The Number toFixed() method is a critical tool in the JavaScript toolkit that provides powerful formatting capabilities to represent numbers in legible ways. This article has explored various examples of how to use this method to remove, round, and pad decimal digits, as well as round numbers represented using exponential notation.
We also learned about common exceptions related to using the toFixed() method on non-numeric values and how to mitigate these exceptions in code. By mastering these concepts, you’ll be able to optimize your numerical representations in your JavaScript code.
Remember, always take care to handle exceptions properly and to ensure the data type of your inputs before using the toFixed() method.