Built in packages & String Class

boolean equals(String str); Compares the contents of two “string” objects.

boolean equalsIgnoreCase(String str); Compare the content of two “string” objects ignores case.

import java.lang.*;
class App35
{
public static void main(String yck[])
{
String s=new String("CHAITANYA");
String y=new String("chaitanya");
if(s.equalsIgnoreCase(y))
System.out.println("The two Strings are equal");
else
System.out.println("The two strings are not equal");
}
}


output:

\>javac App35.java
\>java App35
The two Strings are equal

import java.lang.*;
class extra1
{
public static void main(String yck[])
{
String s=new String("CHAITANYA");
String y=new String("chaitanya");
boolean result;
result=s.equals(y);
if(result == true)
System.out.println("The two Strings are equal");
else
System.out.println("The two strings are not equal");
}
}


output:

\>javac extra1.java
\>java extra1
The two strings are not equal

boolean regionMatches(int startindex, String str1, int str2Startindex, int numChars);

boolean regionMatches(boolean ignorescase, int startindex, String str, int str2startindex, int numChars); Compares the range of characters in one string object with the range of characters in the another string object.

str2 : Specifies the destination String being compared to.str2startindex : Specifies the no. of characters to compare.ignorecase : When set to true ignores the case.

import java.lang.*;
class App36
{
public static void main(String yck[])
{
String x=new String("application");
String y=new String("CATEGORY");
boolean result;
result=x.regionMatches(5,y,0,3);
if(result == true)
System.out.println("The Region Matches");
else
System.out.println("The Region is not Matching");
}
}


output:

\>javac App36.java
\>java App36
The Region is not Matching

import java.lang.*;
class extra2
{
public static void main(String yck[])
{
String x=new String("application");
String y=new String("CATEGORY");
boolean result;
result=x.regionMatches(true,5,y,0,3);
if(result == true)
System.out.println("The Region Matches");
else
System.out.println("The Region is not Matching");
}
}


output:

\>javac extra2.java
\>java extra2
The Region Matches

boolean startWith(String str); Determine whether the invoking “String” object starts with the contents of ‘str’.

boolean endsWith(String str); Determine whether the invoking string object ends with the contents of ‘str’.

import java.lang.*;
class App37
{
public static void main(String yck[])
{
String x=new String("notepad");
String y=new String("note");
String z=new String("pad");
if(x.startsWith(y))
System.out.println("Yes");
else
System.out.println("No");
if(x.endsWith(z))
System.out.println("Yes");
else
System.out.println("No");
}
}


output:

\>javac App37.java
\>java App37
Yes
Yes

int compareTo(String str); Compare the contents of the invoking ‘String’ object with ‘str’.
Return values:

0 if both Strings are equal.<0 if length of first string is less than that of second string.>0 if length of first string is greater than that of second string.

import java.lang.*;
class App38
{
public static void main(String yck[])
{
String x=new String("notepad");
String y=new String("notepad");
if(x.compareTo(y)==0)
System.out.println("The two strings are equal");
else
System.out.println("The two strings are not equal");
}
}


output:

\>javac App38.java
\>java App38
The two strings are equal

int indexOf(char ch); Returns the first occurrence of ‘ch’ in the invoking String object.

int lastIndexOf(char ch); Returns the last occurrence of ‘ch’ is the involving String objects.

import java.lang.*;
class App39
{
public static void main(String yck[])
{
String x=new String("notepad");
System.out.println(x.indexOf('o'));
System.out.println(x.lastIndexOf('p'));
}
}


output:

\>javac App39.java
\>java App39
1
4

String subString(int startindex); Extracts a sub string from a string.

String subString(int startindex, int numchar); Extracts a specified number of characters from the invoking string object.

import java.lang.*;
class App40
{
public static void main(String yck[])
{
String s=new String("foxpro");
String s1=s.substring(3);
String s2=s.substring(0,3);
System.out.println(s1);
System.out.println(s2);
}
}


output:

\>javac App40.java
\>java App40
pro
fox

String concat(String str); Concatenates the contents of the object "str" with that of the invoking object.

import java.lang.*;
class App41
{
public static void main(String yck[])
{
String x=new String("Oracle");
String y=new String(" is a date base");
String z=x.concat(y);
System.out.println(z);
}
}


output:

\>javac App41.java
\>java App41
Oracle is a date base