What's the difference between double quotes and single quote in C#

Question

What\'s the difference between double quotes and single quote in C#?

I coded a program to count how many words are in a file

using System;
using Syst         


        

Answer 1

the single quote represent a single character 'A', double quote append a null terminator '\0' to the end of the string literal, " " is actually " \0" which is one byte larger than the intended size.

Answer 2

Single quotes instead of double ones?

Where? Here? if(text[i] == " ")

text[i] gives a character/byte and this is compared to an array of (probably unicoded ??) characters/bytes. That does not work well.

Say: compare '1' with 1
or "1" with "one" or (2-1) with "eins" what do you think are the correct answers, or is there no meaningful answer anyway?

Besides that: the program will not work very well with single quotes either, given the example "words.txt" =

one word or 2 words or more words here ?

Answer 3

when you say string s = "this string" then s[0] is a char at at specific index in that string (in this case s[0] == 't')

So to answer your question, use double quotes or single quotes, you can think of the following as meaning the same thing:

string s = " word word";

// check for space as first character using single quotes
if(s[0] == ' ') {
 // do something
}

// check for space using string notation
if(s[0] == " "[0]) {
 // do something
}

As you can see, using a single quote to determine a single char is a lot easier than trying to convert our string into a char just for testing.

if(s[0] == " "[0]) { 
 // do something
}

is really like saying:

string space = " ";
if(s[0] == space[0]) {
 // do something
}

Hopefully I did not confuse you more!

Answer 4

you are looking for spaces, this can be done as a space in a string or as a char. So in my opinion this would work.

(By the way, if the file contains sentences with dots. And someone forgot to add a space after the dot, the word will not be added to the total amount of words)

Answer 5

Single quotes encode a single character (data type char), while double quotes encode a string of multiple characters. The difference is similar to the difference between a single integer and an array of integers.

char c = 'c';
string s = "s"; // String containing a single character.
System.Diagnostics.Debug.Assert(s.Length == 1);
char d = s[0];

int i = 42;
int[] a = new int[] { 42 }; // Array containing a single int.
System.Diagnostics.Debug.Assert(a.Length == 1);
int j = a[0];