Contents
Javascript is a powerful scripting language. In this blog post, we will show you how to convert a string to an integer in Javascript.
Checkout this video:
Introduction
In JavaScript, there are 3 main ways to convert a string to an integer. These are:
-The parseInt() method
-The Number() method
-The unary operator +
What is a string?
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.
What is an integer?
In computer science, an integer is a data type that represents mathematical integers. They are often stored as a signed 32-bit number, from -2,147,483,648 to 2,147,483,647. Integers can be stored in other formats, such as 16-bit or 64-bit, but they are typically converted to this format for ease of use and compatibility.
The parseInt() function
The parseInt() function parses a string and returns an integer. The radix parameter is used to specify which base to use, for example, a radix of 16 (hexadecimal) indicates that the number in the string should be parsed from a base-16 number.
If the string argument is not a string, then it is converted to a string (using the ToString abstract operation). Leading whitespace in the string argument is ignored. An optional plus or minus sign may precede the number.
Using the parseInt() function
The parseInt() function parses a string and returns an integer. The function takes two arguments: the string to be parsed and the radix (base). For example, to convert the string “10” to the integer 10, you would use parseInt(“10”, 10).
If the first argument is not a string, it is converted to a string before starting the parsing. If the radix is not specified, it defaults to 10. If the radix is specified, it must be an integer between 2 and 36.
The parseInt() function can also be used with other bases:
parseInt(“11”, 2); // returns 3 (1*2^1 + 1*2^0 = 3)
parseInt(“ff”, 16); // returns 255 (15*16^1 + 15*16^0 = 255)
Examples of using the parseInt() function
The parseInt() function is a built-in function in JavaScript that can be used to convert a string to an integer. The function takes two arguments, the string to be converted and the radix (the base of the number in the string). The function returns an integer or NaN (not a number) if the string could not be converted.
If the radix parameter is omitted, the function will try to determine the base of the number from the string. If the string begins with “0x”, “0X” or “#”, it will be interpreted as a hexadecimal number; if it begins with “0b” or “0B”, it will be interpreted as a binary number; otherwise, it will be interpreted as a decimal number.
Here are some examples of using parseInt() to convert strings to integers:
“`javascript
parseInt(“1234”); // returns 1234
parseInt(“1234”, 10); // returns 1234
parseInt(“01234”); // returns 1234 (base 10)
parseInt(“0x1234”); // returns 4660 (base 16)
parseInt(“0b10101”); // returns 21 (base 2)“`
Converting strings to numbers in JavaScript
JavaScript includes two additional primitive data types, Boolean and Null, which we’ll learn about in the next section.
There are two main ways to convert a string to a number in javascript. First, you can use the parseInt() function which takes an input string and an optional base into which the string is to be parsed. If you don’t provide a base, JavaScript assumes you want to convert from base 10. The second way is to use the Number() function which also takes an input string and an optionalradix parameter. If you don’t specify a radix, again JavaScript assumes you want to convert from base 10.
So, for example, if you have a string like “1”, you can convert it to the number 1 using either parseInt() or Number():
parseInt(“1”); // returns 1
Number(“1”); // also returns 1
If you have a string like “3.14” you can again use either parseInt() or Number():
parseInt(“3.14”); // returns 3 (the integer part of the number)
Number(“3.14”); // returns 3.14 (the whole number)
The Number() function
The Number() function converts the object argument to a number that represents the object’s value. If the value cannot be converted, it returns NaN.
If the argument is a string, it is converted to a number by first stripping non-numeric characters and then converting to an integer or floating point number. decimals are not parsed. Strings with a “0x” prefix are parsed as hexadecimals; strings with any other prefix are parsed as decimal numbers.
Using the Number() function
In JavaScript, you can represent a number as a string. For example, the number 3 can be represented as a string as “3”.
The Number() function converts a string to a number. So if you have a string such as “3”, and you want to convert it to an integer, you can use the Number() function like this:
Number(“3”) // returns 3
Examples of using the Number() function
Javascript has a built-in function called Number() which will convert a string to an integer number. In this article, we’ll look at how to use the Number() function and also go over some examples.
Number() takes in an argument and tries to convert it into a number data type. If the argument can’t be converted into a number, then Number() will return NaN (not a number).
Here are some examples of using Number():
Number(“1234”) // returns 1234
Number(“hello”) // returns NaN
Number(“”) // returns 0
As you can see from the examples above, if the string can be converted into a number, then Number() will return the numeric value. If the string can’t be converted, then it will return NaN.
