jQuery toUpperCase/toLowerCase Example

JavaScript code snippet to convert text to UpperCase and to LowerCase. Simple Example provided for your amusements – shows case changes for form value form inputs.

See: The jQuery titleCaps Function


jQuery('form').submit(function() {
    jQuery('input#value').val(function(i, val) {
          return val.toUpperCase();
           return val.toLowerCase();
    });
 });

Frequently Asked Questions (FAQs) about jQuery toUpperCase() and toLowerCase() Methods

What is the difference between jQuery toUpperCase() and toLowerCase() methods?

The jQuery toUpperCase() and toLowerCase() methods are used to change the case of text in JavaScript. The toUpperCase() method converts a string to uppercase letters, while the toLowerCase() method converts a string to lowercase letters. These methods do not change the original string but return a new string in the desired case.

How can I use the toLowerCase() method in jQuery?

The toLowerCase() method in jQuery is quite simple to use. You just need to call the method on the string you want to convert to lowercase. Here’s an example:
var str = "Hello World!";
var lowerCaseStr = str.toLowerCase();
console.log(lowerCaseStr); // Outputs: "hello world!"
In this example, the string “Hello World!” is converted to lowercase using the toLowerCase() method.

Can I use the toUpperCase() method on numbers or special characters?

The toUpperCase() method in jQuery only affects alphabetic characters. Numbers, special characters, and whitespace are not affected by this method. If you call toUpperCase() on a string that contains only numbers or special characters, the original string will be returned without any changes.

Are the toUpperCase() and toLowerCase() methods case-sensitive?

No, the toUpperCase() and toLowerCase() methods in jQuery are not case-sensitive. They will convert all alphabetic characters in the string to the desired case, regardless of their original case.

Can I use the toUpperCase() and toLowerCase() methods with other jQuery methods?

Yes, you can chain the toUpperCase() and toLowerCase() methods with other jQuery methods. This is a common practice in jQuery and can make your code more concise and easier to read.

How can I convert only the first letter of a string to uppercase in jQuery?

To convert only the first letter of a string to uppercase in jQuery, you can use the charAt() method in combination with the toUpperCase() method. Here’s an example:
var str = "hello world!";
var firstLetterUpperCaseStr = str.charAt(0).toUpperCase() + str.slice(1);
console.log(firstLetterUpperCaseStr); // Outputs: "Hello world!"
In this example, the first letter of the string “hello world!” is converted to uppercase.

What happens if I call the toLowerCase() method on an empty string?

If you call the toLowerCase() method on an empty string in jQuery, it will return another empty string. The toLowerCase() method does not change the original string, so calling it on an empty string will not produce any errors or unexpected results.

Can I use the toUpperCase() and toLowerCase() methods in jQuery on non-string data types?

The toUpperCase() and toLowerCase() methods in jQuery are designed to work with strings. If you try to use these methods on non-string data types, you will get a TypeError. To avoid this, you should always make sure that the data you are working with is a string before calling these methods.

Are the toUpperCase() and toLowerCase() methods in jQuery supported in all browsers?

Yes, the toUpperCase() and toLowerCase() methods are part of the ECMAScript standard for JavaScript and are supported in all modern browsers, including Chrome, Firefox, Safari, and Edge.

How can I convert a string to title case in jQuery?

To convert a string to title case in jQuery, you can use a combination of the toLowerCase() and toUpperCase() methods along with the split() and join() methods. Here’s an example:
var str = "hello world!";
var titleCaseStr = str.toLowerCase().split(' ').map(function(word) {
return word.charAt(0).toUpperCase() + word.slice(1);
}).join(' ');
console.log(titleCaseStr); // Outputs: "Hello World!"
In this example, the string “hello world!” is converted to title case, which means the first letter of each word is capitalized.