What is Type Conversion in JavaScript

Type conversion refers to process of converting data from one type to another. For example, you may change a number into a string or a string into a number. Type conversion in JavaScript can be done implicitly (by JavaScript automatically) or explicitly (by the programmer manually).

Converting Strings to Numbers

Type conversion of strings to numbers is often needed in JavaScript applications, especially for handling user inputs.

Number Methods

Number methods in JavaScript help manipulate and format numeric values effectively.

1. Using Number()

The Number() function converts a string to a number.

Example

let str = “123”; let num = Number(str); console.log(num); // Output: 123 console.log(typeof num); // Output: number

Important Note:

Ensure to handle cases where the string might not be a valid number to avoid unexpected results like NaN.

2. Using parseInt() and parseFloat()

parseInt() converts a string to an integer.
parseFloat() converts a string to a floating-point number.

Example

let intStr = “456”; let floatStr = “78.90”; console.log(parseInt(intStr)); // Output: 456 console.log(parseFloat(floatStr)); // Output: 78.9

The Unary + Operator

In JavaScript, you can quickly turn strings into numbers by using the unary + operator.

Example

let str = “42”; let num = +str; console.log(num); // Output: 42 console.log(typeof num); // Output: number

Important Note:

Ensure that the string is purely numeric to avoid NaN.

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What is Type Conversion in JavaScript