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Java char Array - char array in java

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char Array in Java

char Array

Java char Array

Java char array is used to store char data type values only. In the Java programming language, unlike C, an array of char is not a String, and neither a String nor an array of char is terminated by '\u0000' (the NUL character). The Java platform uses the UTF-16 representation in char arrays and in the String and StringBuffer classes. Char Arrays are highly advantageous. The char arrays prove to be simplistic and efficient. Java char arrays are faster, as data can be manipulated without any allocations.

With the following Java char array examples you can learn

  • how to declare Java char array
  • how to assign values to Java char array
  • how to get values from Java char array

What is a char in Java ?

char is a primitive data type in Java. char is a any character of a Java character set. The default value of a char data type is '\u0000'. char variable capable of storing following values. The literal char enclosed with single quotes.

  • char can store any alphabet.
  • char can store a number 0 to 65535.
  • char can store a special character. E.g. !, @, #, $, %, ^, &, *, (, ), ¢, £, ¥
  • char can store unicode (16 bit) character.

How to Declare char Array in Java ?

Arrays are declared with [] (square brackets). If you put [] (square brackets) after any variable of any type only that variable is of type array remaining variables in that declaration are not array variables those are normal variables of that type.

If you put [] (square brackets) after any data type all the variables in that declaration are array variables. All the elements in the array are accessed with index. The array element index is starting from 0 to n-1 number i.e. if the array has 5 elements then starting index is 0 and ending index is 4.

Declaring Java char Array

Declaration of a char array can be done by using square brackets. The square brackets can be placed at the end as well.

//declaring Java char array
char[] java_char_array;
char java_char_array[];

What is the Default Value of Char in Java ?

In Java, the default value of char is "u0000". Default value of char data type in Java is '\u0000' . The default value of a char primitive type is '\u0000'(null character) as in Java

Related : Java boolean Array

How to Initialize char Array in Java ?

The char array will be initialized to '\u0000' when you allocate it. All arrays in Java are initialized to the default value for the type. This means that arrays of ints are initialised to 0, arrays of booleans are initialised to false and arrays of reference types are initialised to null.

Initializing Java char Array

A char array can be initialized by conferring to it a default size.

//initializing java char array
char[] java_char_array = new char[10];

What is the Length of an Array in Java ?

In Java all the arrays are indexed and declared by int only. That is the size of an array must be specified by an int value and not long or short. All the arrays index beginning from 0 to ends at 2147483646. You can store elements upto 2147483647. If you try to store long (big) elements in array, you will get performance problems. If you overcome performance problems you should go to java collections framework or simply use Vector.

Syntax :

< data type > < variable >[];
< data type >[] < variable >;

Related : Java byte Array

Java char Array Example

/*  Java char Array Example
    Save with file name CharArray.java  */
public class CharArray
{
	public static void main(String args[])
	{
		// JAVA CHAR ARRAY DECLARATION
		char c[];
		// MEMORY ALLOCATION FOR JAVA CHAR ARRAY
		c = new char[4];
		// ASSIGNING ELEMENTS TO JAVA CHAR ARRAY
		c[0] = 'a';
		c[1] = 'c';
		c[2] = 'D';
		c[3] = 'B';
		// JAVA CHAR ARRAY OUTPUT
		System.out.println("Java char Array Example");
		for(int i=0;i<c.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + c[i]);
		}
	}
}

Related : Java short Array

Following Java char array example you can learn how to assign values to char array at the time of declaration.

How to assign values to char array at the time of declaration

/*  How to assign values to char array at the time of declaration Example
    Save with file name CharArray2.java */
public class CharArray2
{
	public static void main(String args[])
	{
		// JAVA CHAR ARRAY DECLARATION AND ASSIGNMENT
		char c[] = {'a', 'c', 'D', 'B'};
		// JAVA CHAR ARRAY OUTPUT
		System.out.println("Java char Array Example");
		for(int i=0;i<c.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + c[i]);
		}
	}
}

Related : Java int Array

Following Java char array example you can learn how to declare Java char array with other Java char array variables.

How to declare Java char array with other Java char array variables

/*  How to declare Java char array with other Java char array variables Example
    Save with file name CharArray3.java */
public class CharArray3
{
	public static void main(String args[])
	{
		// JAVA CHAR ARRAY DECLARATION
		// c IS AN ARRAY a IS NOT AN ARRAY
		char c[], a;
		// MEMORY ALLOCATION FOR JAVA CHAR ARRAY
		c = new char[4];
		// ASSIGNING ELEMENTS TO JAVA CHAR ARRAY
		c[0] = 'a';
		c[1] = 'c';
		c[2] = 'D';
		c[3] = 'B';
		a = 'X';
		// JAVA CHAR ARRAY OUTPUT
		System.out.println("Java char Array Example");
		System.out.println("a value is : "+a);
		for(int i=0;i<c.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + c[i]);
		}
	}
}

Related : Java float Array

How to assign Java char array to other Java char array

Following Java char array example you can learn how to assign Java char array to other Java char array.

/*  How to assign Java char array to other Java char array Example
    Save with file name CharArray4.java */
public class CharArray4
{
	public static void main(String args[])
	{
		// JAVA CHAR ARRAY DECLARATION
		char[] c, a; // c AND a ARE ARRAY VARIABLES
		// MEMORY ALLOCATION FOR JAVA CHAR ARRAY
		c = new char[4];
		// ASSIGNING ELEMENTS TO JAVA CHAR ARRAY
		c[0] = 'a';
		c[1] = 'c';
		c[2] = 'D';
		c[3] = 'B';
		// ASSIGNING c ARRAY TO a ARRAY VARIABLE
		a = c;
		// JAVA CHAR ARRAY OUTPUT
		System.out.println("Java char Array Example");
		System.out.println("c array values");
		for(int i=0;i<c.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + c[i]);
		}
		System.out.println("a array values");
		for(int i=0;i<a.length;i++)
		{
			System.out.println("Element at Index : "+ i + " " + a[i]);
		}
	}
}

Related : Java long Array

How to Convert String to char Array in Java ?

Sometimes you need to convert String to the character array in java programs or convert a String to char from specific index. String class has three methods related to char. Let’s look at them before we look at a Java program to convert string to char array. Let’s look at a simple string to char array java program example.

  1. char[] toCharArray() : This method converts string to character array. The char array size is same as the length of the string.
  2. char charAt(int index) : This method returns character at specific index of string. This method throws StringIndexOutOfBoundsException if the index argument value is negative or greater than the length of the string.
  3. getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) : This is a very useful method when you want to convert part of string to character array. First two parameters define the start and end index of the string; the last character to be copied is at index srcEnd-1. The characters are copied into the char array starting at index dstBegin and ending at dstBegin + (srcEnd-srcBegin) – 1.

String to char array java – convert string to char

The following example converting string to char array and string to char Java.

/*  How to Convert String to char Array in Java Example
    Save with file name StringToCharArray.java */
public class StringToCharArray.java
{
	public static void main(String[] args)
	{
		String str = "How to Convert String to char Array in Java";
		// CONVERT STRING TO CHAR ARRAY
		char[] string_char_array = str.toCharArray();
		System.out.println(string_char_array.length);
		// CHAR AT SPECIFIED INDEX
		char c = str.charAt(2);
		System.out.println(c);
		// COPY PART OF STRING TO CHAR ARRAY
		char[] char_array = new char[8];
		str.getChars(0, 8, char_array, 0);
		System.out.println(char_array);
	}
}

Related : Java double Array