C# equivalent to Java's charAt()?

Taking care of bounds

Unlike Java's charAt() which throws StringIndexOutOfBoundsException, C# lobs an IndexOutOfRangeException if the index isn't playing by the rules. Keep a check on the index like a strict guard:

string str = "Hello";
int index = 5; // Bounds are off since "Hello" is 5 letters long.
if (index >= 0 && index < str.Length)
{
    char c = str[index];
    // Begin the character dance!
}
else
{
    // Time to handle the rebel index!
}
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Manipulating characters like a boss

Nested within direct indexing is a powerful key to tweaking characters in strings. Meet StringBuilder, your C# genie that grants wishes:

StringBuilder sb = new StringBuilder("Hello");
sb[0] = 'Y'; // Goodbye 'H', hello 'Y'!
Console.WriteLine(sb.ToString()); // Outputs "Yello" 
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No room for array-out-of-bounds errors here!

Just like running into a wall hurts, exceeding string boundaries can hurt your program. Always validate indices, it's like wearing a safety helmet
:

string secureAccess(string str, int index) =>
    index >= 0 && index < str.Length ? str[index].ToString() : null;

Console.WriteLine(secureAccess("Hello", 1)); // Outputs: 'e'
Console.WriteLine(secureAccess("Hello", 10)); // Outputs: null  ...Wall avoided!
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Optimizing performance 



Handling large strings or traversing the choppy waters of performance-critical code? Each indexing operation comes at a price:

1. Avoid indexing inside tight loops, it's like standing at the edge. Better to store the character in a cozy local variable.
2. When dealing with a gang of consecutive characters, Substring is your friendly neighborhood superhero.