How new string(Char[]) works in c#?-CodePudding

I'm studing C# for two weeks. And I have problem, I don't know how 4th line of this code works, namely new string(charArray)

string s = "Hello";
char[] charArray = s.ToCharArray();
Array.Reverse(charArray);
Console.WriteLine(new string(charArray));

Thank you all for responding!

CodePudding user response：

string s = "Hello";

This creates a new string, “Hello” assigned to a variable s

char[] charArray = s.ToCharArray();

This takes each character in the string s and puts it into an array: [ 'H', 'e', 'l', 'l', 'o' ]

Array.Reverse(charArray);

This takes the array and reverses the contents: [ 'o', 'l', 'l', 'e', 'H' ]. This does the operation in memory to the array itself so you don’t need to reassign it.

Console.WriteLine(new string(charArray));

This is doing two things: Assigning a new string that will contain each character in the array and then that value is being passed into Console.WriteLine which will write to the console output stream:

olleH

You could break that up into two statements for clarity:

string s = new string(charArray);
Console.WriteLine(s);

CodePudding user response：

The new keyword means we are calling a constructor for the string type, specifically one that expects a char[] as an argument.