Strings In Java Language [full-Explanation] - Tricks For Coding

Strings, which are generally utilized as a part of Java, for writing computer programs, are a grouping of characters.........

Strings in Java:

Strings, which are generally utilized as a part of Java, for writing computer programs, are a grouping of characters. In the Java programming language, strings are like everything else, objects. The Java platform provides the String class to make and control strings.

Instantiating Strings:

The most appropriate approach to make a string is to use the following statement:

String mystring = “Hi world!”;

At whatever point it experiences a string exacting in your code, the compiler makes a

String object with its value for this situation, “Hi world!’.

Similarly, as with other objects, you can make Strings by utilizing a constructor and a new keyword. The String class has eleven constructors that permit you to give the starting estimation of the string utilizing diverse sources, for example, a cluster of characters.

class Main {
  public static void main(String[] args) {
    // create first string
    String first = "Introduction To Strings ";
    System.out.println("First String: " + first);
    // create second
    String second = "To Java By Tricks For Coding";
    System.out.println("Second String: " + second);
    // join two strings
    String joinedString = first.concat(second);
    System.out.println("Joined String: " + joinedString);
  }
}

Result First String: Introduction To Strings Second String: To Java By Tricks For Coding Joined String: Introduction To Strings To Java By Tricks For Coding

Note: The String class is changeless so that once it is made a String object, its type can’t be changed. In the event that there is a need to make a lot of alterations to the Strings of characters, then you ought to utilize String Buffer & String Builder Classes.

Determining String Length:

Routines used to get data about an object are known as accessor methods. One accessor technique that you can use with strings is the length() function, which furnishes a proportional payback of characters contained in the string item. This function can be utilized in the following manner:

public class Test {
    public static void main(String[] args)
    {
        // Here str is a string object
        String str = "Tricks For Coding";
        System.out.println(
            "The size of "
            + "the String is "
            + str.length());
    }
}

Result The size of the String is 17

How to Concatenate Strings:

The String class incorporates a function for connecting two strings:

mystring1.concat(mystring2);

This returns another string that is mystring1 with mystring2 added to it toward the end. You can likewise utilize the concat() system with string literals, as in:

“My name is “.concat(“mary”);

Strings are all the more usually concatenated with the + administrator, as in:

“Hi,” + ” world” + “!”

which brings about:

“Hi, world!”

Sample Implementation:

class Concatenation{  
 public static void main(String args[]){  
   String s1="Tricks For Coding";  
   String s2=", The Best Website for Coding & Tech related content.";  
   String s3=s1.concat(s2);  
   System.out.println(s3);
  }  
}  

Result Tricks For Coding, The Best Website for Coding & Tech related content.

Format Strings:

You have format() and printf() functions to print the output with designed numbers. The function format() of the String class returns a String object as against a Printstream object. This function creates a formatted string that can be reused. This function can be used in the following manner:

public class FormatExample{  
public static void main(String args[]){  
String name="Tricks For Coding";  
String sf1=String.format("name is %s",name);  
String sf2=String.format("value is %f",45.77);  
String sf3=String.format("value is %32.12f",45.77);
System.out.println(sf1);  
System.out.println(sf2);  
System.out.println(sf3);  
}}  

Result name is Tricks For Codingvalue is 45.770000 value is 45.770000000000

String Methods:

This section contains a list of methods that are available as part of the String class.

• int compareTo(Object obj) – This function compares the specified string with the object concerned.
• char charAt(int chindex) – This function returns the char present at the index value ‘index.’
• int compareToIgnoreCase(String mystr) – This function performs the lexographic comparison of the two strings. However, the case differences are ignored by this function.
• int compareTo(String aString) – This function performs the lexographic comparison between the strings.
• boolean contentEquals(StringBuffer strb) – This function checks if the string is same as the sequence of characters present in the StringBuffer. It returns true on success and false on failure.
• String concat(String strnext) – This function appends the string with another string at the end.
• static String copyValueOf(char[] mydata, int xoffset, int xcount) – This function returns a stringf, which is indicative of the character sequence in the original string.
• static String copyValueOf(char[] newdata) – This function copies the string of characters into a character buffer in the form of a sequence of characters.
• boolean equals(Object aObject) – This function compares the object with the string concerned.
• boolean endsWith(String newsuffix) – This function appends the string with the specified suffix.
• byte getBytes() – Using this function, the string can be encoded into bytes format, which are stored in a resultant array.
• boolean equalsIgnoreCase(String aString) – This function makes a comparison of the two strings without taking the case of characters into consideration.
• void getChars(int srcBegin, int sourceEnd, char[] dst, int destinationBegin) – This function copies characters from the specified beginning character to the end character into an array.
• byte[] getBytes(String charsetnm) - Using this function, the string can be encoded into bytes format using a named char set, which is stored in a resultant array.
• int indexOf(int charx) – This function returns the index of the first character that is the same as the character specified in the function call.
• int hashCode() – A hash code is returned by this string.
• int indexOf(String newstr) - This function returns the index of the first occurrence of a substring in a string.
• int indexOf(int charx, int fromIndexloc) – This function returns the index of the first character that is same as the character specified in the function call. The search starts from the specified index.
• String intern() – A canonical representation of a string object given in the function call is returned.
• int indexOf(String newstr, int fromIndexloc) - This function returns the index of the first occurrence of a substring in a string. The search starts from the specified index.
• int lastIndexOf(int charx, int fromIndexloc) - This function makes a search for a character from the specified index and returns the index where the last occurrence is found. 
• int lastIndexOf(int charx) - This function makes a search for a character backward and returns the index where the last occurrence or first occurrence in a backward search is found.
• int lastIndexOf(String newstr, int fromIndexloc) – This function makes a search for a substring from the specified index and returns the index where the last occurrence is found.
• int lastIndexOf(String newstr) - This function makes a search for a sub-string backwards and returns the index where the last occurrence or first occurrence in a backward search is found.
• boolean matches(String aregex) - – This function checks for equality between a string region and a regular expression.
• int length() – This function calculates and returns the string length.
• boolean regionMatches(int totaloffset, String otherstr, int otheroffset, int strlen) – This function checks for equality between string regions.
• boolean regionMatches(boolean ignorecharcase, int totaloffset, String otherstr, int otheroffset, int strlen) – This function checks for equality between string regions.
• String replace(char oldCharx, char newCharx) - This function looks for a substring that matches the regular expression and then replaces all the occurrences with the specified string. The function returns the resultant string, which is obtained after making all the replacements.
• String replaceFirst(String newregex, String newreplacement) – This function looks for a substring that matches the regular expression and then replaces the first occurrence with the specified string.
• String replaceAll(String newregex, String xreplacement) - This function looks for a substring that matches the regular expression and then replaces all the occurrences with the specified string.
• String[] split(String newregex, int xlimit) – This function performs splitting of the string according to the regular expression with it and the given limit.
• String[] split(String newregex) - This function performs splitting of the string according to the regular expression with it.
• boolean startsWith(String newprefix, int totaloffset) – This function checks if the given string has the prefix at the specified index.
• boolean startsWith(String newprefix) – This function checks if the given string begins with the prefix sent with the function call.
• String substring(int beginIndexloc) - This function returns a string, which is substring of the specified string. The substring is determined by the beginning index to the end of the string.
• CharSequence subSequence(int beginIndexloc, int endIndexloc) - This function returns a character sequence, which is sub-character sequence of the specified character sequence. The substring is determined by the beginning and ending indexes
• char[] toCharArray() – This function performs the conversion of a string to a character array.
• String substring(int beginIndexloc, int endIndexloc) – This function returns a string, which is a substring of the specified string. The substring is determined by the beginning and ending index.
• String toLowerCase(Locale localenew) - This function converts all the characters in the specified string to lowercase using given locale rules.
• String toLowerCase() - This function converts all the characters in the specified string to lowercase using default locale rules.
• String toUpperCase() - This function converts all the characters in the specified string to upper case using default locale rules.
• String toString() – This function returns the string itself.
• String toUpperCase(Locale localenew) – This function converts all the characters in the specified string to upper case using locale rules.
• static String valueOf(primitive data type x) – A string representation is returned by this function.
• String trim() – Omits the whitespace that trails and leads a string.