package com.ack.learning;
/**
* messing about with Java Strings
*/
public class SimpleStrings {
public static void main( String[] args ) {
// a string is a array of characters
char[] helloChars = {'h', 'e', 'l', 'l', 'o'};
String helloString = new String( helloChars );
System.out.println( helloString );
// best way to assign a string literal
helloString = "hello";
// no need to do this
helloString = new String( "hello" );
// an example
String barryWhite = "i love you all!";
System.out.println( barryWhite.length() ); // 15
System.out.println( barryWhite.charAt( 0 ) ); // i
System.out.println( barryWhite.startsWith( "i love" ) ); // true
System.out.println( barryWhite.endsWith( "all" ) ); // false
System.out.println( barryWhite.indexOf( 'l' ) ); // 2
System.out.println( barryWhite.indexOf( "you" ) ); // 7
System.out.println( barryWhite.substring( 7 ) ); // you all!
System.out.println( barryWhite.substring( 3, 8 ) ); // ove y
// String equality
String a = "hello";
String b = "world";
String c = new String( "hello" );
String d = a;
// == between Java objects is on reference equality
// equals() method is used to value equality
System.out.println( a == b ); // false
System.out.println( a == c ); // false
System.out.println( a.equals( c ) ); // true
System.out.println( a == d ); // true
// String are immutable
String noChange = "have i changed, not likely";
noChange.substring( 3 );
noChange.toLowerCase();
noChange.toUpperCase();
noChange.trim();
System.out.println( noChange ); // have i changed, not likely
// StringBuffer usage
StringBuffer buffer = new StringBuffer();
for( int i = 0; i < 10; i++ ) {
buffer.append( "say hello: " );
buffer.append( i );
buffer.append( "\n" );
}
System.out.println( buffer );
/**
* this outputs
* say hello: 0
* say hello: 1
* say hello: 2
* say hello: 3
* say hello: 4
* say hello: 5
* say hello: 6
* say hello: 7
* say hello: 8
* say hello: 9
*/
}
}