C vs Java Strings

String in C

In C, we can define a string as a bunch of characters. A character array is distinguished from a string by the presence of the special character '\0' at the end of the string.

Declaration of String:

A string can be declared in the same way that a one-dimensional array can. The normal syntax for the declaration of a string is shown below.

Syntax:

char str_name[size];

In the following syntax, the str name is any name supplied to the string variable, and size is used to define the string's length or the number of characters it may hold. Keep in mind that the Null character (\'0') is used to distinguish strings from normal character arrays.

Initializing a string:

A string can be started in a variety of ways. With the help of a simple example, we shall illustrate this. An example of declaring a string with the name str and initializing it with "Helloworld" is shown below.

1. char str[] = "Helloworld";

2. char str[30] = "Helloworld"

3. char str[] = {'h','e','l','l','o','w','o','r','l','d','\0'};

4. char str[11] = {'H','e','l','l','o','w','o','r','l','d','\0'};

Example:

// C program to illustrate strings

#include<stdio.h>
int main()
{
// initialize a string
char str[] = "helloworld";
// print a string
printf("%s",str);
return 0;
}

Output:

Helloworl

Strings can be printed using standard print statements, just like any other variable, as shown in the above program. The printing of a string character by character, as we will do with arrays, is not necessary. Despite having an inherent data type for strings, the C programming language does have an access specifier called "percent s" that may be used to print and read texts directly.

Example: PROGRAM TO TAKE/READ INPUT FROM USER

#include<stdio.h>
int main(){
// declaring a string
char str[70]; //We can input 70 characters in this string
// reading string
scanf("%s",str);
// print string
printf("%s",str);
return 0;
}

As you can see in the preceding example, a single scanf statement can also be used to read a string. You might be asking why the scanf command didn't include the '&' symbol with the string name "str"! To understand this, you'll need to think back on your understanding of scanf.

We already know that the variable's address is sent to the scanf() function via the symbol "&," which causes it to save the value it receives in memory. Using str without the brackets '[' and ']' yields the base address of the string since str[] is a character array. Since we are already providing scanf with the base address of the string, we didn't utilize '&' in this case.

Example to pass string to a particular function:

#include<stdio.h>
void printStr(char str[])
{
printf("String is : %s",str);
}
int main()
{
// declare and initialize string
char str[] = "Helloworld";
// print string by passing argument 
printStr(str);
return 0;
}

Output:

A string is : Helloworld

String in Java

Strings are Objects in Java that are internally supported by a char array. Strings are immutable because arrays are also immutable (they can not grow). Whenever you make an edit to a String, a new String will be produced.

Syntax:

<String_Type> <string_variable> = "<sequence_of_string>"; 

Memory allotment of String in Java

A String Object will be formed in the String constant pool whenever it is created as a literal. As a result, the initialization of String literals can be optimized by JVM.

Example:

String str = "Hello";

The string can also be dynamically allocated by using the new operator. Strings that are dynamically allocated are given a new memory position in a heap. The String constant pool will not include this string.

Example:

import java.io.*;
import java.lang.*;
class Test {
	public static void main(String[] args)
	{
	// Declaring a string without using new operator
	String s = "Helloworld";
	System.out.println("String s = " + s);
	// Declare String using new operator
	String s1 = new String("Helloworld");
	System.out.println("String s1 = " + s1);
	}
}

Output:

String s = Helloworld
String s1 = Helloworld

Creating Strings

The casual way to create a string in Java is to write:-

String s = “Java Strings”;

The compiler constructs a String object with the value "Java Strings!" whenever it determines a string clause in your code.

Like any other object, a string object can’t be created with the use of a new keyword and the Object function. There are eleven constructors available in the String class, and you may choose the string's starting value from one of these sources—including an array of characters.

The second method of creating a string is:-

String s = new String (“Tutorialandexample”);

String Buffer:-

StringBuffer is a string fellow class that gives plenty of similar performance as strings. While string displays fixed-length, immutable character sequences, StringBuffer displays character sequences that are modifiable and growable.

Syntax:

StringBuffer s = new StringBuffer("Hello World");

String Tokenizer:-

Tokenizing a string in Java can be done with the help of StringTokenizer class.

String Joiner:-

A series of characters may be built using the String Joiner class from the Java.util package, which can also start with a transferred prefix and end with a transferred suffix.

Syntax:

public StringJoiner(CharSequence delimiter);

As we have shown in the preceding section, we have an adequate understanding of replacing a character in a string.

So, there are three ways to replace character in a string:

StringBuilder:

Unlike the String Class, the StringBuilder class has a built-in method for this — setCharAt() (). You can replace the character at a certain position by executing this function and passing the character and index as inputs.

Difference between C String and Java Strings

C	Java
A string in C is usually just an array of (or a pointer to) chars that ends with the NUL (0) character. A string can be processed just like any other array.	Strings, on the other hand, are not arrays in Java. The java. lang. The string class has instances (objects) that are used to create Java strings. Although the programmer has no access to the actual implementation, they represent character data. Although you cannot manipulate them like arrays, you can, if required, extract string data as an array of bytes or characters (methods getBytes and getChars). Also, Java chars are usually 16-bits, whereas C chars are typically (but not always) 8-bits.
Strings in C are mutable.	Strings in Java are immutable.
Syntax: char str_name[size];	Syntax <String_Type> <string_variable> = "<sequence_of_string>";