why we can assign both int value and a char value to Character Wrapper type. Autoboxing means boxing for the corresponding wrapper but Character is not the corresponding wrapper of int. It is Integer
why both of these statements are possible
Character character = 'a';
Character character2 = 3;
It is treated as an ASCII value, if you assign int value to Character.
Below 4 approach result in same output.
Character character2 = 'e';
Character character2 = 101;
int i = 101;
Character character2 = (char)i; // casting int to char i.e. treat it as ASCII value
Character character2 = (char)101;
System.out.println(character2); // Prints e
Note: You can refer this ASCII Table
3 is not necessarily an int. it is short type. Both char and short are 16 bit in length
It is the ASCII value assigned to the character.
In the first case
Character character1 = 'a';
The character1 is directly assigned a character value.
But in your second statement:
Character character2 = 3;
character2 is assigned the ASCII value of 3 which is ?
Related
I'm not quite sure why this piece of code involving array of characters makes sense?
String str1 = "Hello"
int[] charSet = new int[128];
char[] chars = str1.toCharArray();
for (char c : chars) { // count number of each char in s.
if (charSet[c] == 0)++charSet[c];
}
My Question is how is it you can char variable as an index for the charSet array and compare it to 0?
A char is an unsigned 16-bit numeric type, and will be widened to int when used as an array index.
charSet[c] is implicitly charSet[(int) c]
Note that the code will fail if non-ASCII characters are in the string, because only ASCII characters are in Unicode code point range 0-127. Any other Unicode character will cause ArrayIndexOutOfBoundsException.
the code with my comments.
String str1 = "Hello";
int[] charSet = new int[128];// ascii chars a-z and A-Z go from 65-122 using a 128 array is just being lazy
char[] chars = str1.toCharArray();
for (char c : chars) { //loop though each character in the string
if (charSet[c] == 0)//c is the character converted to int since it's all a-z A-Z it's between 65 and 122
++charSet[c];//if it the character hasn't been seen before set to 1
}
Is there a java library to convert special characters into decimal equivalent?
example:
input: "©™®"
output: "& #169; & #8482; & #174;"(space after & is only for question purpose, if typed without a space decimal equivalent is converted to special character)
Thank you !
This can be simply achieved with String.format(). The representations are simply the character value as decimal, padded to 4 characters and wrapped in &#;
The only tricky part is deciding which characters are "special". Here I've assumed not digit, not whitespace and not alpha...
StringBuilder output = new StringBuilder();
String input = "Foo bar ©™® baz";
for (char each : input.toCharArray()) {
if (Character.isAlphabetic(each) || Character.isDigit(each) || Character.isWhitespace(each)) {
output.append(each);
} else {
output.append(String.format("&#%04d;", (int) each));
}
}
System.out.println(output.toString());
You just need to fetch the integer value of the character as mentioned in How do I get the decimal value of a unicode character in Java?.
As per Oracle Java doc
char: The char data type is a single 16-bit Unicode character. It has
a minimum value of '\u0000' (or 0) and a maximum value of '\uffff' (or
65,535 inclusive).
Assuming your characters fall within the character range, you can just get the decimal equivalent of each character from your string.
String text = "©™®";
char[] cArr = text.toCharArray();
for (char c : cArr)
{
int value = c; // get the decimal equivalent of the character
String result = "& #" + value; // append to some format string
System.out.println(result);
}
Output:
& #169
& #8482
& #174
I have a String containing ASCII representation of a character i.e.
String test = "0x07";
Is there a way I can somehow parse it to its character value.
I want something like
char c = 0x07;
But what the character exactly is, will be known only by reading the value in the string.
You have to add one step:
String test = "0x07";
int decimal = Integer.decode(test);
char c = (char) decimal;
I want to know that how to recognize and print next character in ASCII sequence if input is a non- string value like "space" or "!".
I know that for string value we can convert it into ASCII value by using
char character = 'a';
int ascii = (int) character;
Then adding 1 to it and converting it back to char , we can get next value in the sequence .
You can use:
char character = 'a';
int ascii = (char)((int)character+1);
It should work. But I have haven`t tested it.
I have a program and I need to understand it, but I don't understand two lines of it.
Okay so there is one-dimensional array - int [] names,
and two chars - char let1, let2.
Now, there is a command:
char let1 = names[i].charAt(names[i].length()-1);
char let2 = names[i+1].charAt(0);
What does that mean?
let1 is assigned the last character of names[i] and let2 is assigned the first character of names[i+1].
char let1 = names[i].charAt(names[i].length()-1);
It means find out the string at index i of String array names and from that String extract out the character at the last index of that String. And then assign that character value to the char variable let1.
char let2 = names[i+1].charAt(0);
It means extract out the String at index i+1 from String array names and from that String extract out the character at first index (0) . And then assign that character value to the char variable let2.