JavaScript Numbers
JavaScript has a built-in number data type that represents numeric values. JavaScript numbers can be integers or floating-point numbers (decimal). Numbers in JavaScript are basic data types. Unlike other programming languages, you do not need to specify distinct numeric values using int, float, and so on.
1. Integers
An integer is a whole number, which means it does not have a fractional part. In JavaScript, integers are represented as a numeric data type called "number". Integers can be positive, negative or zero.
2. Floating
A floating-point number (or "float" for short) is a numeric data type that represents a decimal number in JavaScript. Unlike integers, floating-point numbers have a fractional part, which allows for more precise representation of non-integer values.
3. Numeric Strings
A numeric string is a string that contains a numeric value. JavaScript allows you to perform arithmetic operations on numeric strings, but it's important to note that the resulting value will still be a string.
4. NaN - Not a Number
NaN is a special numeric value that represents an undefined or undefined value. When you try to perform an operation that doesn't make sense, such as dividing zero by zero or converting a non-numeric string to a number, NaN is returned.
5. Infinity
Infinity is a special numerical value that represents positive infinity. When a number exceeds the upper limit of the floating-point number range, infinity is returned.
6. Hexadecimal
JavaScript supports hexadecimal notation for representing numbers. A hexadecimal number is a base-16 number that uses the digits 0-9 and the letters A-F to represent values from 0 to 15.
7. Numbers as Objects
In addition to the primitive Number data type, JavaScript also has a Number object type that allows you to work with numbers as objects. The Number object type provides additional properties and methods for working with numbers.
FAQs
In JavaScript, numbers are used to represent numeric values, including integers and floating-point numbers. They are a fundamental data type in JavaScript and are extensively used for performing mathematical calculations, storing quantities, and handling numeric data in web applications. JavaScript provides various arithmetic operators and built-in functions for manipulating and working with numbers. Understanding JavaScript numbers is crucial for tasks like calculations, data validation, and implementing mathematical algorithms.
JavaScript provides several methods for converting strings to numbers. The most commonly used method is parseInt(), which parses a string and returns an integer. For example, parseInt("42") would convert the string "42" to the number 42. If you need to convert a string to a floating-point number, you can use the parseFloat() function. It behaves similarly to parseInt() but preserves the decimal part of the string. Another method is to use the unary plus operator (+), which can convert a string representation of a number into an actual number. For instance, +"3.14" would convert the string "3.14" to the number 3.14. These conversion methods are useful when dealing with user input, reading data from external sources, or performing calculations on numeric strings.
JavaScript provides several methods for rounding numbers. The Math.round() function is used to round a number to the nearest whole number. For example, Math.round(3.6) would return 4, while Math.round(3.2) would return 3. If you want to round a number down to the nearest whole number, you can use Math.floor(). For rounding up, you can use Math.ceil(). Additionally, the toFixed() method allows you to round a number to a specific number of decimal places. For example, var pi = 3.14159; pi.toFixed(2) would return the string "3.14". Rounding numbers is commonly needed for formatting values, displaying calculations, and ensuring accuracy in mathematical operations.