dataconversion.java

一些关于软件质量保证与测试的资料

import java.io.*;

public class DataConversion {

           /*convert a String into an integer
            *integer range from  -2147483647 to 2147483647
            *inputs:
            *if the string has some non-digits, just convert the first digits into
            *integers and then report errors, ie. "23ab34" -> 23.
            *if the string has ., just convert the integer part of the number, ie. "345.2" -> 345
            *if the string contains sign of the number, convert it as appropriate
            *ie. "+56" -> 56,  "-34" -> -34
            */
           public int atoi(String s)
           {
		
                int    s_index = 0;     //string index, for conversion
                byte   num_sign = 1;	//sign of the result number
                int   number = 0;  	//result number

                //check the input string length
                if (s.length() <= 0)
				{   System.out.println("input string length is incorrect. should be larger than 0");
					return 0;
				}
				//System.out.println("input string is "+s);
                //check the sign 
                if (s.charAt(0) == '-' || s.charAt(0) == '+')
                {     if (s.charAt(0) == '-')
                         num_sign = -1;
                      s_index = 1;     
				}
                for (int i=s_index; i<s.length(); i++)
                {
					  
                      if (s.charAt(i) >= '0' && s.charAt(i) <= '9')
					  {
						  //System.out.println("string at "+i+" is "+s.charAt(i));
						  number = number*10 + (s.charAt(i) - '0');   
						  
					  }
                      else {
						 if (s.charAt(i) != '.')
							 System.out.println("input string has wrong characters. should be digits 0-9");
                         break;
                      }
                }                
				return num_sign*number;
           }

		   
	
//		   public static void main(String[] args)
//		   {
//			   DataConversion mydc = new DataConversion();
//			   System.out.println("1 is "+mydc.atoi("1"));
//			   System.out.println("-1 is "+mydc.atoi("-1"));
//			   System.out.println("+1 is "+mydc.atoi("+1"));
//			   System.out.println("0 is "+mydc.atoi("0"));
//			   System.out.println("-0 is "+mydc.atoi("-0"));
//			   System.out.println("1.2 is "+mydc.atoi("1.2"));
//			   System.out.println("2-3 is "+mydc.atoi("2-3"));
//			   System.out.println("299.3a is "+mydc.atoi("299.3a"));
//			   System.out.println("abc is "+mydc.atoi("abc"));
//			   System.out.println("a123 is "+mydc.atoi("a123"));
//			   
//			   System.out.println("214748" + mydc.atoi("214748"));
//			   System.out.println("  " + mydc.atio("  "));

//			   System.out.println("max integer is "+Integer.MAX_VALUE);
//			   System.out.println("min integer is "+Integer.MIN_VALUE);
//				
//			   
//			   System.out.println("2147483647 is " + mydc.atoi("2147483647"));
//			   System.out.println("2147483648 is " + mydc.atoi("2147483648"));
//			   System.out.println("-2147483647 is " + mydc.atoi("-2147483647"));
//			   System.out.println("-2147483648 is " + mydc.atoi("-2147483648"));
//				  
//			   
//			   System.out.println("2224859387587563 is " + mydc.atoi("2224859387587563"));
//			   
//		   }


}