How Do I Check if a Variable is a String in JavaScript?

Checking if a Variable is a String in JavaScript

Determining the type of a variable is crucial in JavaScript, especially when working with strings. This article explores a practical method to verify if a variable contains a string or something else.

The Best Approach

A reliable way to determine if a variable is a string is to use the following code:

if (typeof myVar === 'string' || myVar instanceof String)
// it's a string
else
// it's something else

Understanding the Code

• typeof myVar === 'string': Checks if the variable myVar is a string primitive value.
• myVar instanceof String: Determines if myVar is an instance of the String object. This checks for string objects that may have been created using the String constructor.

Additional Notes

• The typeof operator's behavior can be unexpected with special cases like null and undefined.
• Creating a string object using new String() is not recommended as it yields unnecessary complexity.
• String objects have additional methods and properties, while string primitives do not.

The above is the detailed content of How Do I Check if a Variable is a String in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!