toLowerCase()

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toLowerCase() is a method in TypeScript (and in JavaScript) that converts all characters in a string to lowercase. It doesn't modify the original string, but instead returns a new string with all letters converted to lowercase.

Here's an example of how to use toLowerCase() in TypeScript:


In this example, myString contains the original string "Hello World!", and lowerCaseString contains the resulting string after calling toLowerCase(), which is "hello world!".

Here's a more practical use case:

Suppose you have a form where users can input their emails. To ensure there are no capitalization issues when comparing emails later (e.g., when checking if an email is already registered), you can convert all emails to lowercase before saving them to the database. This ensures that even if the user enters their email with uppercase letters or a mixture of cases, it will still be recognized as the same email.


This way, when you need to compare emails, you can simply convert them to lowercase before making the comparison:


This ensures that even if emails are typed in different ways (with uppercase letters, lowercase letters, or a mixture of both), they will still be treated as equal during the comparison.

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