CPP String Data Type

💻 CPP String Data Type – Complete Beginner to Interview Guide

In CPP String Data Type is used to store a sequence of characters (text) such as names, sentences, or messages.

1️⃣ What is String in C++? ⭐

A string is a collection of characters enclosed in double quotes " ".

📌 C++ provides strings using the Standard Template Library (STL).

2️⃣ Header File for String ⭐

📌 Must be included to use string.

3️⃣ Declaring a String Variable ⭐

Syntax

Example

4️⃣ String Example Program ⭐

Output

5️⃣ String Input Using cin ⭐

📌 Reads only one word.

6️⃣ String Input Using getline() ⭐⭐

📌 Reads full line including spaces.

7️⃣ cin + getline() Issue ⚠️

✔ Correct way:

8️⃣ String Length ⭐⭐

Output

📌 .length() or .size() both work.

9️⃣ String Concatenation ⭐⭐

Output

🔟 Accessing Characters in String ⭐⭐

Output

1️⃣1️⃣ Modifying String ⭐⭐

Output

1️⃣2️⃣ String vs Character Array ⭐⭐⭐

1️⃣3️⃣ Common String Errors ❌

❌ Forgetting <string> header
❌ Using cin for multi-word input
❌ Confusing ' ' and " "
❌ Index out of range

📌 Interview Questions (C++ String)

Q1. Difference between cin and getline()?
👉 cin reads one word, getline() reads full line

Q2. How to find length of string?
👉 .length() or .size()

Q3. Is string mutable in C++?
👉 Yes

✅ Summary

✔ string stores text
✔ Uses double quotes
✔ Supports many built-in functions
✔ getline() for full input
✔ Very important for exams & interviews