자바의신 ch14 & ch15

package c.exception.practice;

public class Calculator {
  public static void main(String[] args) {
    Calculator calc = new Calculator();
    try {
      calc.printDivide(1, 2);
      calc.printDivide(1, 0);
    } catch (Exception e) {
      System.out.println(e.getMessage());
    }
  }
  // throws를 사용해서 호출시 try-catch 안에 넣도록 했음
  public void printDivide(double d1, double d2) throws Exception {

    if(d2==0){
      // d2가 0인데 나누기가 실행되면 Infinity가 출력되기 때문에  아래의 메시지를 갖는 예외를 발생시켰다.
      throw new Exception("Second value can't be Zero");
    }
    double result = d1/d2;
    System.out.println(result);
  }
}

package d.string.practice;

import java.util.Locale;

public class UseStringMethod {

  public static void main(String[] args) {
    UseStringMethod a = new UseStringMethod();
    a.printWords("The String class represents character strings.");
    a.findString("The String class represents character strings.", "string");
    a.findAnyCaseString("The String class represents character strings.", "string");
    a.countChar("The String class represents character strings.", 's');
    a.printContainWords("The String class represents character strings.", "ss");

  }
  public void printWords(String str) {
    String[] a = str.split(" ");
    for(String as : a) {
      System.out.println(as);
    }
  }
  public void findString(String str, String findStr) {
    int a = str.indexOf(findStr);
    System.out.println(String.format("%s is appeared at %d", findStr, a));
  }
  public void findAnyCaseString(String str, String findStr) {
    String a = str.toLowerCase();
    int b = a.indexOf(findStr);
    System.out.println(String.format("%s is appeared at %d", findStr, b));
  }

  public void countChar(String str, char c) {
    char[] a = str.toCharArray();
    int count = 0;
    for(char as : a) {
      if(c == as) {
        count++;
      }
    }
    System.out.println("char " + "'"+c+ "' count is " + count);
  }
  public void printContainWords(String str, String findStr) {
    String [] a = str.split(" ");
    for(String as : a ) {
      if(as.contains(findStr)) {
        System.out.println(as + " contains " + findStr);
      }
    }
  }
}