Know about how to extract a number from a String in JavaScript?

Here are a few ways you can extract a number from a string in JavaScript:

1. Use a regular expression: You can use a regular expression to match and extract a number from a string. For example:

function extractNumber(string) {
var match = string.match(/\d+/);
return match ? match[0] : null;
}

var number = extractNumber("The price is $12.99");
console.log(number); // Output: 12.99

In this example, we use the String.match() method and a regular expression to match and extract a number from the string. The regular expression looks for one or more digits (\d+) and returns the first match it finds. If a match is found, the function returns the first element of the match array (the number); if no match is found, the function returns null.

2. Use the parseInt() or parseFloat() functions: You can use the parseInt() or parseFloat() functions to convert a string that contains a number to a number data type. For example:

var number = parseInt("123", 10);
console.log(number); // Output: 123

var decimal = parseFloat("3.14");
console.log(decimal); // Output: 3.14

In this example, we use the parseInt() function to convert the string “123” to the integer 123, and the parseFloat() function to convert the string “3.14” to the floating point number 3.14.

3. Use the Number() function: You can use the Number() function to convert a string that contains a number to a number data type. For example:

var number = Number("123");
console.log(number); // Output: 123

var decimal = Number("3.14");
console.log(decimal); // Output: 3.14