String class : JAVA Programming by "Gopal Krishna"

public class astr
{
public static void main(String arg[])
{
String s1="sachin";
String s2="SACHIN";
String s3="mohan";
String s4=new String("sachin");
String s5=new String("mohan");
String s6=new String("sachin");
String s7="sachin";
String s18=" sachin ";

if(s1.equals(s7))
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1.equals(s2))
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1.equalsIgnoreCase(s2))
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

int a=s1.compareTo(s2);
{
System.out.println("this is="+a);
}

int b=s1.compareToIgnoreCase(s2);
{
System.out.println("this is="+b);
}

int c=s1.compareTo(s3);
{
System.out.println("this is="+c);
}

int d=s3.compareTo(s1);
{
System.out.println("this is="+d);
}


String s8=s1.concat(s2);
{
System.out.println(s8);
}


String s9=s1.concat("  hello");
{
System.out.println(s9);
}

String s10=s1.substring(2);
{
System.out.println(s10);
}

String s11=s3.substring(3);
{
System.out.println(s11);
}

String s12=s1.substring(0,3);
{
System.out.println(s12);
}

String s13=s2.substring(3,5);
{
System.out.println(s13);
}


if(s1.startsWith("sa"))
{
System.out.println("yes");
}
else
{
System.out.println("no");
}

if(s1.endsWith("ni"))
{
System.out.println("yes");
}
else
{
System.out.println("no");
}


int e=s1.length();
{
System.out.println(e);
}

String s15=s3.toUpperCase();
{
System.out.println(s15);
}

String s16=s15.toLowerCase();
{
System.out.println(s16);
}

String s19=s18.trim();
{
System.out.println(s19);
}

int p=s1.indexOf("h");
{
System.out.println(p);
}

char q=s1.charAt(3);
{
System.out.println(q);
}

if(s1==s2)
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1==s6)
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1==s5)
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1==s3)
{
System.out.println("same");
}
else
{
System.out.println("not same");
}

if(s1==s7)
{
System.out.println("same");
}
else
{
System.out.println("not same");
}
}
}