Considering you are a programmer, you may have heard the term “String,” multiple times. For any programmer, learning everything about strings can be a tedious task. String is defined as nothing but a combination of characters.
However, let’s simplify the concept for you and understand in depth what strings are. Not only that, you must get a brief of what a string subsequence is. Also, make sure you know how to find the longest palindromic subsequence.
Learn The Primary Concept Behind A String: Character Encoding
As mentioned above, Strings are just a combination of characters. However, when it comes to computers, they do not understand characters in a way we do, and also, they do not save them in their memory in the same way.
Therefore, characters are stored in the memory in the form of binary numbers. A convention is used to define which number will represent which character.
Now, when visually represented, your computer will represent these numbers in the form of characters that you see. This whole process is known as character encoding.
Other than this, a lot of programmers assume that all the characters are similar and are single bytes. Well, that is not the case. Almost all the Unicode characters can be stored as 2-byte or 16-bit data.
With more than 136,000 points present in Unicode, only 65,536 characters can be stored in two bytes. Therefore, it is important to have a multi-byte to store the remaining ones.
Moreover, when it comes to the length of the encoding, the length can be variable. The length can be either variable or fixed. Let’s get an idea of what these different types of encodings are:
- UTF 16: UTF-16 is a common encoding type used that represents a single 16-bit character type. This simply means that UTF-16 is variable-length encoding that uses 16 bits (minimum) and 32 bits( maximum).
- UTF- 32: UTF-32 is a fixed-length encoding that occupies four bytes for each character.
- UTF-8: When it comes to UTF-8, it utilizes four 8 bits to encode each Unicode point. UTF-8 is a variable-length encoding type.
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Explore Some Basic Terms Related To Strings
Now that you are aware of what Character encoding is, let’s explore some terms related to Strings that will come in handy while understanding more about string operations.
Substring
A substring of any string can be defined as a string that appears in the original string.
Let’s clear this with an example,
Consider a string: Ball
Substrings of the string “Ball” are:
“ba,” “bal,” “all,” “al.”
Well, in this example, all the substrings mentioned appear in the original string, which is “Ball.”
Prefix
The prefix of a string can be defined as its substring, which appears at the beginning of that string.
To understand the concept of Prefix better, consider the string “Ball.”
The prefix of the string Ball will be:
“Ba,” “Bal,” “b,” “ball.”
So, in this example, all the prefix strings mentioned appear at the beginning of your original string. So, to be a prefix, the String should be present at the beginning of the original String.
Suffix
Unlike Prefix, a suffix string is a string that occurs at the end of the Original string.
Here is an example of a String “Ball” to explain the concept better.
“all,” “ll,” “l”
In this example, all the suffixes mentioned appear at the end of the original string. So, in order to call a string a suffix string, it appears at the end of the string.
Subsequence
The subsequence of a string is defined as a sequence of characters from the string without changing the location of the original characters.
To simplify this concept, let’s consider an example of String “Ball.”
“al” is the subsequence of a string as it appears in the same sequence in the original string “Ball.”
However, when it comes to “la,” this is not a subsequence as it does not appear in the same sequence as that of the original string.
Take A Brief Of All String Operations
Now let’s proceed with a brief of all the operations you can perform on a string.
Case Folding
Case folding is a means to convert all the characters of a string to the same case, i.e., uppercase or lowercase.
Case folding or capitalization can be used in different scenarios.
One such scenario is when you have to compare two strings in the same case. In that case, you will have to convert both strings to the same case. However, the process is not always that simple.
Concatenation
Concatenation is nothing but connecting two strings.
For example, if there are two strings: “mickey” and “mouse,” After concatenation, both the strings will be concatenated together into one string and will look like “mickey mouse.”
Tokenize
Another operation that you can carry out on a string is Tokenizing it. Tokenizing the token means breaking down a single string into different strings on the basis of a Delimiter.
For example: consider the string “How Are You? “.
When you tokenize your string, it will look like [ “How,” “Are,” “You”].
Longest Palindromic Subsequence
The longest Palindromic Subsequence is an operation on a string that allows you to find the longest subsequence of a string which is also a palindrome.
For example: Consider the string ABBCDABB.
If you check the longest palindromic subsequence of this string, you will get the output: BBABB, which is 5 characters long.
So, the longest Palindromic subsequence for your given string will be of 5 characters.
Print All Subsequence Of A String
Another operation that you can perform on a string is to print all subsequences of a string.
For example: if you input a string “ABC.”
You will get the following output:
“a,” “b,” “c,” “ab,” “bc,” “ac,” “abc”
Print all subsequences of a string function will print and list out all the subsequences of your given string.
Conclusion
Learning about strings is important if you wish to learn each and every aspect of programming. Though, strings are not just some characters. There’s a lot more to it.
In this guide, we have tried to explain about strings, operations on strings, longest Palindromic subsequence, character encoding, and a lot more! So that you can get a better insight on the concepts related to strings.
