String in Data Structure Last Updated : 06 Jul, 2025 Summarize Suggest changes Share Like Article Like Report A string is a sequence of characters. The following facts make string an interesting data structure.Small set of elements. Unlike normal array, strings typically have smaller set of items. For example, lowercase English alphabet has only 26 characters. ASCII has only 256 characters.Strings are immutable in programming languages like Java, Python, JavaScript and C#. Many String Problems can optimized using the fact that the character set size is small. For example sorting can be done faster, counting frequencies of items is faster and many interesting interview questions are based on this.Basics of Strings:Introduction to StringsString in different language:Strings in C String Class in C++String in JavaPython StringC# | StringJavaScript StringPHP | StringsBasic Operations of String:Length of a StringCheck if two strings are sameSearch a Character Insert a Character at a PositionRemove a Character at a PositionInsert a character at Multiple PositionsRemove all occurrences of a characterConcatenating Two StringsReverse a stringGenerate all SubstringsPlease refer String Problems Topic Wise for the list of questions on different topics like binary string, subsequence and substring, pattern searching and palindrome.Easy Problems on String:Check for BinaryCamel Case ConversionBinary Substrings with Corners as 1sCheck for PanagramCheck for PalindromeCheck for SubstringCheck for SubsequenceCheck for Anagrams Check for K-AnagramsDuplicates in a StringLongest Substring Between Equals Check for RotationGenerate all binary strings from given pattern Smallest and Largest Word in a StringCount number of equal pairs in a stringSecond most repeated word in a sequenceAll strings by placing spacesSort string of charactersChar Frequencies in Order of OccurrenceChar Frequencies in Alphabetical order URLify a given stringMedium Problems on String:First Repeating CharacterFirst Non-Repeating CharacterK’th Non-repeating CharacterImplement atoi Add 2 Binary Strings Add n Binary StringsMultiply 2 Strings Divide large numberIsomorphic StringsRemove AdjacentRoman to IntegerInterleaved StringsPermutations of a StringLongest Palindromic SubstringQueries for characters in a repeated stringCount anagram substringsCount binary strings without consecutive 1’sLexicographically next stringSplit String into four distinct stringsWord Break ProblemLength of Longest Balanced SubsequenceMinimum Swaps for Bracket BalancingString to mobile numeric keypad sequenceMinimum number from given sequenceShortest path to print a string on screenMirror characters of a stringHard Problems on String:Lexicographic Rank of a StringMultiply Large Numbers Ways to increase LCS length of 2 strings by oneMin rotations required to get the same stringFind if an array of strings can be chained to form a circleAlien DictionaryMake two strings AnagramMake two Strings Anagram Without DeletionPalindrome Substring QueriesPowet Set in Lexicographic orderMinimum Word BreakWord Search - 8 Directions and Straight MovementWord Search - 4 Directions and Zig-Zag AllowedMinimum number of bracket reversals needed to make an expression balancedWord Wrap problem ( Space optimized solution )Decode a string recursively encoded as count followed by substring Advertise with us Next Article Hashing in Data Structure H harendrakumar123 Follow Similar Reads DSA Tutorial - Learn Data Structures and Algorithms DSA (Data Structures and Algorithms) is the study of organizing data efficiently using data structures like arrays, stacks, and trees, paired with step-by-step procedures (or algorithms) to solve problems effectively. 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