String

Understanding Strings in Data Structures

A string is a sequence of characters that represents text. In most programming languages, strings are treated as objects with various built-in methods for text manipulation and processing.

Visualizing Strings

Here’s a visualization of a string: String Visualization

Core Concepts

Character Sequence

Strings are sequences of characters that can include letters, numbers, symbols, and special characters.

Memory Representation

Each character in a string typically occupies a fixed amount of memory (e.g., 1 byte for ASCII, 2 or 4 bytes for Unicode).

String Properties

Strings can be immutable (Java, Python) or mutable (like char arrays in C++), affecting how they're manipulated.

String Operations Implementation

1. String Creation and Access

// String creation
string str = "Hello World";

// Accessing characters
char firstChar = str[0];
char lastChar = str.back();

// String length
size_t length = str.length();

# String creation
string = "Hello World"

# Accessing characters
first_char = string[0]
last_char = string[-1]

# String length
length = len(string)

// String creation
let str = "Hello World";

// Accessing characters
let firstChar = str[0];
let lastChar = str[str.length - 1];

// String length
let length = str.length;

2. String Operations

string str = "Hello World";

// Concatenation
string str2 = "!";
string result = str + str2;

// Substring
string sub = str.substr(0, 5); // "Hello"

// Find
size_t pos = str.find("World"); // Returns 6

// Replace
str.replace(0, 5, "Hi"); // "Hi World"

string = "Hello World"

# Concatenation
result = string + "!"

# Substring
sub = string[0:5]  # "Hello"

# Find
pos = string.find("World")  # Returns 6

# Replace
new_string = string.replace("Hello", "Hi")

let str = "Hello World";

// Concatenation
let result = str + "!";

// Substring
let sub = str.substring(0, 5); // "Hello"

// Find
let pos = str.indexOf("World"); // Returns 6

// Replace
let newStr = str.replace("Hello", "Hi");

3. String Traversal Methods

string str = "Hello";

// Using index-based loop
for(int i = 0; i < str.length(); i++) {
    cout << str[i] << " ";
}

// Using range-based loop
for(char c : str) {
    cout << c << " ";
}

// Using iterator
for(string::iterator it = str.begin(); it != str.end(); it++) {
    cout << *it << " ";
}

string = "Hello"

# Using index-based loop
for i in range(len(string)):
    print(string[i], end=" ")

# Using for-each loop
for char in string:
    print(char, end=" ")

# Using enumerate
for i, char in enumerate(string):
    print(f"Index {i}: {char}")

let str = "Hello";

// Using for loop
for(let i = 0; i < str.length; i++) {
    console.log(str[i]);
}

// Using for...of
for(let char of str) {
    console.log(char);
}

// Using split and forEach
str.split('').forEach(char => {
    console.log(char);
});