Stream Operations

🌊 C++ Stream Operations: Your Data’s Adventure Through Pipes!

Imagine you have a water park with pipes that carry water to different pools. In C++, streams are just like those pipes—they carry your data (words, numbers) from one place to another!

Today, we’ll explore three magical tools that help you control how water (data) flows through your pipes:

• Stream Manipulators 🎛️ – The control knobs on your pipes
• String Streams 📦 – A special bucket that holds text
• Formatted Output 🎨 – Making your water sparkle beautifully

🎛️ Stream Manipulators: The Control Knobs

What Are They?

Think of stream manipulators like remote control buttons for your TV. Each button changes something on the screen. In C++, manipulators change how your data looks when it comes out!

The Magic Words You Need

#include <iostream>
#include <iomanip>
using namespace std;

The <iomanip> header is like opening a toolbox full of special controls!

🔢 Number Formatting Manipulators

setw(n) – Setting the Width

Imagine you’re putting toys in boxes. setw(n) says: “Use a box that’s n spaces wide!”

cout << setw(10) << 42;
// Output: "        42"
// (8 spaces + 2 digits = 10 total)

setfill(c) – Filling Empty Space

Don’t like empty space? Fill it with something!

cout << setfill('*') << setw(10) << 42;
// Output: "********42"

setprecision(n) – Decimal Places

How many numbers after the dot?

cout << fixed << setprecision(2);
cout << 3.14159;
// Output: "3.14"

📍 Alignment Manipulators

Where should your text sit in its box?

// Left side (like sitting on the left of a bench)
cout << left << setw(10) << "Hi";
// Output: "Hi        "

// Right side (like sitting on the right)
cout << right << setw(10) << "Hi";
// Output: "        Hi"

🔄 Base Manipulators

Numbers can wear different costumes!

int num = 255;
cout << "Decimal: " << dec << num;  // 255
cout << "Hex: " << hex << num;      // ff
cout << "Octal: " << oct << num;    // 377

✨ Boolean & Showpoint Manipulators

bool happy = true;
cout << boolalpha << happy;   // "true"
cout << noboolalpha << happy; // "1"

double x = 5.0;
cout << showpoint << x;  // "5.00000"

📦 String Streams: The Magic Bucket

What’s a String Stream?

Imagine a bucket that can hold text. You can:

• Pour things INTO it (like writing)
• Pour things OUT of it (like reading)
• Mix different things together!

#include <sstream>

🎭 Three Types of Buckets

graph TD
    A["String Streams"] --> B["ostringstream"]
    A --> C["istringstream"]
    A --> D["stringstream"]
    B --> E["Write Only"]
    C --> F["Read Only"]
    D --> G["Read & Write"]

📝 ostringstream – The Output Bucket

Pour things in, get a string out!

ostringstream oss;
oss << "I am " << 10 << " years old!";
string result = oss.str();
// result = "I am 10 years old!"

Real Life Use: Building messages piece by piece!

📖 istringstream – The Input Bucket

Put a string in, pull pieces out!

string data = "Alice 25 3.5";
istringstream iss(data);

string name;
int age;
float grade;

iss >> name >> age >> grade;
// name = "Alice", age = 25, grade = 3.5

Real Life Use: Breaking apart text like a sentence!

🔄 stringstream – The Do-It-All Bucket

Read AND write!

stringstream ss;
ss << 42;           // Put number in
string text;
ss >> text;         // Pull string out
// text = "42"

🎯 Converting Between Types

Number to String:

int num = 123;
stringstream ss;
ss << num;
string str = ss.str();  // "123"

String to Number:

string str = "456";
stringstream ss(str);
int num;
ss >> num;  // 456

🎨 Formatted Output: Making Things Pretty

The Art of Beautiful Display

Formatted output is like being a chef who presents food beautifully. The food tastes the same, but presentation matters!

📊 Creating Tables

cout << left << setw(15) << "Name"
     << right << setw(8) << "Score" << endl;
cout << left << setw(15) << "Alice"
     << right << setw(8) << 95 << endl;
cout << left << setw(15) << "Bob"
     << right << setw(8) << 87 << endl;

Output:

Name               Score
Alice                 95
Bob                   87

💰 Money Formatting

double price = 19.5;
cout << fixed << setprecision(2);
cout << "quot; << setfill('0')
     << setw(6) << price;
// Output: "$019.50"

🔬 Scientific Notation

For really big or tiny numbers:

double big = 1234567890.0;
cout << scientific << big;
// Output: "1.234568e+09"

cout << fixed << big;
// Output: "1234567890.000000"

📱 Combining Everything

Here’s a complete example that uses ALL our tools:

#include <iostream>
#include <iomanip>
#include <sstream>
using namespace std;

int main() {
    // Build a report using stringstream
    ostringstream report;

    // Header with formatting
    report << setfill('=') << setw(30)
           << "" << endl;
    report << "   SCORE REPORT" << endl;
    report << setfill('=') << setw(30)
           << "" << endl;

    // Data rows
    report << left << setfill(' ');
    report << setw(15) << "Player"
           << setw(10) << "Score" << endl;
    report << setw(15) << "Mario"
           << setw(10) << 1500 << endl;

    // Print the report
    cout << report.str();
    return 0;
}

🗺️ The Complete Flow

graph TD
    A["Your Data"] --> B{Choose Your Tool}
    B --> C["Stream Manipulators"]
    B --> D["String Streams"]
    B --> E["Formatted Output"]
    C --> F["Control Width"]
    C --> G["Control Precision"]
    C --> H["Control Alignment"]
    D --> I["Build Strings"]
    D --> J["Parse Strings"]
    D --> K["Convert Types"]
    E --> L["Pretty Tables"]
    E --> M["Money Format"]
    E --> N["Scientific Numbers"]
    F --> O["Beautiful Output!"]
    G --> O
    H --> O
    L --> O
    M --> O
    N --> O
    I --> O
    J --> O
    K --> O

🎮 Quick Reference Card

💡 Remember This!

1. Include <iomanip> for formatting tools
2. Include <sstream> for string streams
3. setw() only affects the NEXT item – use it each time!
4. setprecision() with fixed for exact decimal places
5. String streams are perfect for type conversion

🚀 You Did It!

You now know how to:

• ✅ Control how numbers and text appear
• ✅ Use string streams like magic buckets
• ✅ Create beautiful, formatted output

Think of yourself as a data artist—you can make information look exactly how you want! 🎨

The pipes are yours to control. The water flows where you tell it. Go build something amazing! 🌊