[java] Convert int to char in java

Below is a code snippet,

int a = 1;
char b = (char) a;
System.out.println(b);

But what I get is empty output.

int a = '1';
char b = (char) a;
System.out.println(b);

I will get 1 as my output.

Can somebody explain this? And if I want to convert an int to a char as in the first snippet, what should I do?

This question is related to java char int

The answer is


Make sure the integer value is ASCII value of an alphabet/character.

If not then make it.

for e.g. if int i=1

then add 64 to it so that it becomes 65 = ASCII value of 'A' Then use

char x = (char)i;

print x

// 'A' will be printed 

int a = 1;
char b = (char) (a + 48);

In ASCII, every char have their own number. And char '0' is 48 for decimal, '1' is 49, and so on. So if

char b = '2';
int a = b = 50;

if you want to print ascii characters based on their ascii code and do not want to go beyond that (like unicode characters), you can define your variable as a byte, and then use the (char) convert. i.e.:

public static void main(String[] args) {
    byte b = 65;
    for (byte i=b; i<=b+25; i++) {
        System.out.print((char)i + ", ");
    }

BTW, the ascii code for the letter 'A' is 65


There is one method by which int can be converted to char and even without using ASCII values.

Example:

int i = 2;
char ch = Integer.toString(i).charAt(0);
System.out.println(ch);

Explanation :

First the integer is converted to string and then by using String function charAt(), character is extracted from the string. As the integer only has one single digit, the index 0 is given to charAt() function.


Nobody has answered the real "question" here: you ARE converting int to char correctly; in the ASCII table a decimal value of 01 is "start of heading", a non-printing character. Try looking up an ASCII table and converting an int value between 33 and 7E; that will give you characters to look at.


int a = 1;
char b = (char) a;
System.out.println(b);

will print out the char with Unicode code point 1 (start-of-heading char, which isn't printable; see this table: C0 Controls and Basic Latin, same as ASCII)

int a = '1';
char b = (char) a;
System.out.println(b);

will print out the char with Unicode code point 49 (one corresponding to '1')

If you want to convert a digit (0-9), you can add 48 to it and cast, or something like Character.forDigit(a, 10);.

If you want to convert an int seen as a Unicode code point, you can use Character.toChars(48) for example.


you may want it to be printed as '1' or as 'a'.

In case you want '1' as input then :

int a = 1;
char b = (char)(a + '0');
System.out.println(b);

In case you want 'a' as input then :

int a = 1;
char b = (char)(a-1 + 'a');
System.out.println(b);

java turns the ascii value to char :)


It seems like you are looking for the Character.forDigit method:

final int RADIX = 10;
int i = 4;
char ch = Character.forDigit(i, RADIX);
System.out.println(ch); // Prints '4'

There is also a method that can convert from a char back to an int:

int i2 = Character.digit(ch, RADIX);
System.out.println(i2); // Prints '4'

Note that by changing the RADIX you can also support hexadecimal (radix 16) and any radix up to 36 (or Character.MAX_RADIX as it is also known as).


If we are talking about class types - not primitives, the following trick has to be done:

Integer someInt;
Character someChar;

someChar = (char)Integer.parseInt(String.valueOf(someInt));

In java a char is an int. Your first snippet prints out the character corresponding to the value of 1 in the default character encoding scheme (which is probably Unicode). The Unicode character U+0001 is a non-printing character, which is why you don't see any output.

If you want to print out the character '1', you can look up the value of '1' in the encoding scheme you are using. In Unicode this is 49 (the same as ASCII). But this will only work for digits 0-9.

You might be better off using a String rather than a char, and using Java's built-in toString() method:

int a = 1;
String b = toString(a);
System.out.println(b);

This will work whatever your system encoding is, and will work for multi-digit numbers.


Whenever you type cast integer to char it will return the ascii value of that int (once go through the ascii table for better understanding)

    int a=68;
    char b=(char)a;

    System.out.println(b);//it will return ascii value of 68

    //output- D

First, convert the int (or another type) to String,

int a = 1;
String value = String.valueOf(a);

Then, convert that String to char.

char newValue = value.charAt(0);

You can avoid empty output in this way...

System.out.println(newValue);

My answer is similar to jh314's answer but I'll explain a little deeper.

What you should do in this case is:

int a = 1;
char b = (char)(a + '0');
System.out.println(b);

Here, we used '0' because chars are actually represented by ASCII values. '0' is a char and represented by the value of 48.

We typed (a + '0') and in order to add these up, Java converted '0' to its ASCII value which is 48 and a is 1 so the sum is 49. Then what we did is:

(char)(49)

We casted int to char. ASCII equivalent of 49 is '1'. You can convert any digit to char this way and is smarter and better way than using .toString() method and then subtracting the digit by .charAt() method.


If you want to convert a character to its corresponding integer, you can do something like this:

int a = (int) 'a';
char b = (char) a;
System.out.println(b);

This happens because in ASCII there are some items that can not be printed normally.

For example, numbers 97 to 122 are integers corresponding to the lowercase letters a to z.


public class String_Store_In_Array 
{
    public static void main(String[] args) 
    {
        System.out.println(" Q.37 Can you store string in array of integers. Try it.");

        String str="I am Akash";
        int arr[]=new int[str.length()];
        char chArr[]=str.toCharArray();
          char  ch;
        for(int i=0;i<str.length();i++)
        {

            arr[i]=chArr[i];
        }
        System.out.println("\nI have stored it in array by using ASCII value");
        for(int i=0;i<arr.length;i++)
        {

            System.out.print(" "+arr[i]);
        }
        System.out.println("\nI have stored it in array by using ASCII value to original content");
        for(int i=0;i<arr.length;i++)
        {
             ch=(char)arr[i];

            System.out.print(" "+ch);
        }
    }
}

int a = 1;
char b = (char) a;
System.out.println(b);

hola, well i went through the same problem but what i did was the following code.

int a = 1
char b = Integer.toString(a).charAt(0);
System.out.println(b);

With this you get the decimal value as a char type. I used charAt() with index 0 because the only value into that String is 'a' and as you know, the position of 'a' into that String start at 0.

Sorry if my english isn't well explained, hope it helps you.


look at the following program for complete conversion concept

class typetest{
    public static void main(String args[]){
        byte a=1,b=2;
        char c=1,d='b';
        short e=3,f=4;
        int g=5,h=6;
        float i;
        double k=10.34,l=12.45;
        System.out.println("value of char variable c="+c);
        // if we assign an integer value in char cariable it's possible as above
        // but it's not possible to assign int value from an int variable in char variable 
        // (d=g assignment gives error as incompatible type conversion)
        g=b;
        System.out.println("char to int conversion is possible");
        k=g;
        System.out.println("int to double conversion is possible");
        i=h;
        System.out.println("int to float is possible and value of i = "+i);
        l=i;
        System.out.println("float to double is possible");
    }
}

hope ,it will help at least something


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