Typically for local variables I initialize them as late as I can. It's rare that I need a "dummy" value. However, if you do, you can use any value you like - it won't make any difference, if you're sure you're going to assign a value before reading it.
If you want the char equivalent of 0, it's just Unicode 0, which can be written as
char c = '\0';
That's also the default value for an instance (or static) variable of type char.
Typically for local variables I initialize them as late as I can. It's rare that I need a "dummy" value. However, if you do, you can use any value you like - it won't make any difference, if you're sure you're going to assign a value before reading it.
If you want the char equivalent of 0, it's just Unicode 0, which can be written as
char c = '\0';
That's also the default value for an instance (or static) variable of type char.
Either you initialize the variable to something
char retChar = 'x';
or you leave it automatically initialized, which is
char retChar = '\0';
an ascii 0, the same as
char retChar = (char) 0;
What can one initialize char values to?
Sounds undecided between automatic initialisation, which means, you have no influence, or explicit initialisation. But you cannot change the default.
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You could use
char c[] = "abcdefghijklmn".toCharArray();
if you don't mind creating an unnecessary String.
Unlike in C, Strings are objects, and not just arrays of characters.
That said, it's quite rare to use char arrays directly. Are you sure you don't want a String instead?
You can initialize it from a String:
char[] c = "abcdefghijklmn".toCharArray();
However, if what you need is a string, you should simply use a string:
String s = "abcdefghijklmn";
Here's how you convert a String to a char array:
String str = "someString";
char[] charArray = str.toCharArray();
I'd recommend that you use an IDE when programming, to easily see which methods a class contains (in this case you'd be able to find toCharArray()) and compile errors like the one you have above. You should also familiarize yourself with the documentation, which in this case would be this String documentation.
Also, always post which compile errors you're getting. In this case it was easy to spot, but when it isn't you won't be able to get any answers if you don't include it in the post.
you are doing it wrong, you have first split the string using space as a delimiter using String.split() and populate the char array with charcters.
or even simpler just use String.charAt() in the loop to populate array like below:
String ini="Hi there";
char[] array=new char[ini.length()];
for(int count=0;count<array.length;count++){
array[count] = ini.charAt(count);
System.out.print(" "+array[count]);
}
or one liner would be
String ini="Hi there";
char[] array=ini.toCharArray();
So, I'm learning about arrays using int name = new int[5] where it creates a fixed size array (in this case, it has 5 items of arrays).
As for int, it will fill it with 0 in each item as the initial values. For boolean, false. For double, 0.0. For String, null.
But then, I tried create the char array. But, when I printed it out, it shows weird values. This is what it prints out on my command line. What the hell is that?
Also print
vowelsList.size();
for both, and you'll see the difference ;)
Spoiler:
The generic type of the first method is char[], so you'll get a list of size one. It's type is List<char[]>. The generic type of your second code is Character, so your list will have as many entries as the array. The type is List<Character>.
To avoid this kind of mistake, don't use raw types! Following code will not compile:
List<Character> vowelsList = Arrays.asList(new char[]{'a','e','i','o','u'});
Following three lines are fine:
List<char[]> list1 = Arrays.asList(new char[]{'a','e','i','o','u'}); // size 1
List<Character> list2 = Arrays.asList(new Character[]{'a','e','i','o','u'}); // size 5
List<Character> list3 = Arrays.asList('a','e','i','o','u'); // size 5
As @jlordo (+1) said your mistake is in understanding what does your list contain. In first case it contains one element of type char[], so that it does not contain char element a. In second case it contains 5 Character elements 'a','e','i','o','u', so the result is true.
The default value of a char attribute is indeed '\u0000' (the null character) as stated in the Java Language Specification, section §4.12.5 Initial Values of Variables .
In my system, the line System.out.println('\u0000'); prints a little square, meaning that it's not a printable character - as expected.
'\u0000' is the default value for a character. Its decimal equivalent is 0.
When you are declaring some char variable without initializing it, '\u0000' will be assigned to it by default.
see this code
public class Test {
char c;
public static void main(String args[]) throws Exception {
Test t = new Test();
char c1 = '\u0000';
System.out.println(t.c);
System.out.println(c1);
System.out.println(t.c == c1);
}
}
This code will print true for the last print.