String Formatting

Basic Formatting

string firstName = "Zaphod";
string lastName = "Beeblebrox";

// To pring "My name is Zaphod Beeblebrox", this can be done
Console.WriteLine("My name is " + firstName + " " + lastName);

// But this is way easier
Console.WriteLine(string.Format("My name is {0}, {1}", firstName, lastName));

// Swapping parameters. Output = "My name is Beeblebrox, Zaphod"
Console.WriteLine(string.Format("My name is {0} {1}", lastName, firstName));

// Ignores the second parameter
Console.WriteLine(string.Format("My name is {0}", firstName, lastName));

// Error
Console.WriteLine(string.Format("My name is {0} {1}", firstName));

Numerical Formatting

int ageYears = 42;

// Prints "My age is 42"
Console.WriteLine(string.Format("My age is {0}", ageYears));

// Prefixing with one zero. Output = "My age is 042"
Console.WriteLine(string.Format("My age is {0:D3}", ageYears));

double agePrecise = 42.345678;
Console.WriteLine(string.Format("My age is {0:0.#}", agePrecise));
Console.WriteLine(string.Format("My age is {0:0.##}", agePrecise));
Console.WriteLine(string.Format("My age is {0:0.###}", agePrecise));
// Output
// My age is 42.3
// My age is 42.35
// My age is 42.346