Table of content
- Getting Started with Strings
- String Properties and Methods
- Regular Expressions
- String Manipulation
- Working with Dates
- Project Examples
Getting Started with Strings
let greeting = "Hello, World!" creates a variable called greeting with the string value "Hello, World!".
Once we have a string, we can perform numerous operations on it like concatenation, slicing, replacing, and many more. We can also access individual characters within the string using their index (starting from 0).
Here's a quick example that demonstrates some of these operations:
String Properties and Methods
One useful property of strings is their length. You can access the length of a string by using the
length property, which will return the number of characters in the string. For example,
let myString = "Hello World!"; console.log(myString.length); will output
Another useful property is
charAt(), which allows you to access a specific character in a string. For example,
let myString = "Hello World!"; console.log(myString.charAt(0)); will output
There are also many methods that can be used to manipulate strings. One common method is
toUpperCase(), which converts all the characters in a string to uppercase. For example,
let myString = "hello world!"; console.log(myString.toUpperCase()); will output
Another method is
indexOf(), which allows you to find the index of a specific character or substring in a string. For example,
let myString = "hello world!"; console.log(myString.indexOf("o")); will output
One of the most common uses for is in form validation. For example, when filling out a phone number field, you can use a regular expression to ensure that the input is in the correct format (e.g. 123-456-7890). This helps to prevent errors and ensure a smooth user experience.
can also be used to search for specific patterns within large blocks of text. For instance, if you have a document that contains a lot of acronyms, you can use a regular expression to find and replace all instances of those acronyms with their full name. This can save a lot of time and effort compared to manually searching and replacing each instance.
Working with Dates
Another task we frequently encounter when is calculating the time difference between two dates, which is particularly useful when calculating durations or creating countdown timers. The getTime() method returns the number of milliseconds since January 1, 1970, which we can use to calculate the time difference between two dates. We can also use the Date.parse() method to convert a date string into a millisecond value and then compute the time difference.