Mehran Sahami Handout #25 CS 106A October 22, 2007

Mehran Sahami Handout #25 CS 106A October 22, 2007 Strings Examples Based on examples by Eric Roberts and Patrick Young. Checking for palindromes public boolean isPalindrome(String str) { for(int i = 0; i < str.length() / 2; i++) { if (str.charAt(i) != str.charAt(str.length() - (i + 1))) { return false; } } return true; } Reversing strings and a simpler version of checking for palindromes
public String reverseString(String str) { String result = ""; for(int i = 0 ; i < str.length(); i++) { result = str.charAt(i) + result; } return result; } public boolean simpleIsPalindrome(String str) {
return (str.equals(reverseString(str))); } Counting uppercase characters import acm.program.*; public class CountUppercase extends ConsoleProgram { private int countUppercase(String str) { int upperCount = 0; for(int i=0; i<str.length(); i++) { char ch = str.charAt(i); if (Character.isUpperCase(ch)) { upperCount++; } } return upperCount; } public void run() { String str = readLine("Enter String: "); println(countUppercase(str) + " upper case letters"); } }
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Replace first occurrence public String replaceFirstOccurrence(String str, String orig, String repl) { int index = str.indexOf(orig); if (index != -1) { str = str.substring(0, index) + repl + str.substring(index + orig.length()); } return str; }