2013.01.04. The String Class Immutable Strings and Interned Strings String Comparisons String Length, Characters, and Combining Strings Obtaining Substrings.

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2013.01.04 Slide 2 The String Class Immutable Strings and Interned Strings String Comparisons String Length, Characters, and Combining Strings Obtaining Substrings Converting, replaceing, and Splitting Strings Finding a Character or a Substring in a String Slide 3 A string is a sequence of characters. The String class has 11 constructors and more than 40 methods. Declaration: 1. String S = new String(Hello Java); 2. String S = Hello Java; 3. Char[] C = { H, e, l, l, o,, J, a, v, a }; String S = new String(C); Slide 4 A string object is immutable; its content cannot be changed. String object for Java :StringS String object for Java :StringS String object for html :String S = html;String S = Java; X Slide 5 S1.equals(S2): boolean S1.equalsIgnoreCase(S2): boolean S1.compareTo(S2): int S1.compareToIgnoreCase(S2): int. Java.lang.String : http://www.tutorialspoint.com/java/java_strings.htm ( p.327) Slide 6 HelloJava 0 1 2 3 4 5 6 7 8 9 S.charAt(0) Java.lang.String S.length(): int S.charAt(index: int): char S.concat(S2): String S.length() = 10 S.charAt(9) A String object is presented using an array internally. ( p.365) Slide 7 Java.lang.String S.substring(beginIndex: int): String S.substring(beginIndex: int, endIndex: int): String HelloJava 0 1 2 3 4 5 6 7 8 9 S.substring(0,5) ( p.366) Slide 8 : substring method, S1 0~4 characters Slide 9 Java.lang.String S.toLowerCase(): String S.toUpperCase(): String S.trim():String S.replace(oldchar, newchar): String S.replaceFirst(oldString, newString): String S.replaceAll(oldString, newString): String S.split (delimiter: String): String[ ] ( p.367) Slide 10 : 1. S1 lowercase 2. S2 uppercase 3. S1 JAVA C++ 4. String[] names = S1.split(" "); for(String name:names) { System.out.println(name); } Slide 11 Java.lang.String JAVA.indexOf(J) return 0. JAVA.indexOf(A) return 1. JAVA.indexOf(A,2) return 3. JAVA.indexOf(VA) return 2. JAVA.indexOf(ABC,2) return -1. JAVA.lastIndexOf(A) return 3.. ( p.368) Slide 12 : S1 JAVA Slide 13 (Anagrams) Write a method that checks whether two words are anagrams. Two words are anagrams if they contain the same letters in any order. For example,"silent" and "listen" are anagrams. The header of the method is as follows: public static boolean isAnagram(String s1, String s2) Write a test program that prompts the user to enter two strings and, if they are anagrams, displays "anagram", otherwise displays "not anagram". Slide 14 Ppt http://oss.csie.fju.edu.tw/~jastine01/ppt.html

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