comparator.java

来自「a calculator with some methods of java.m」· Java 代码 · 共 33 行

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class Comparator {
	public static boolean compare(String v1,String v2){
		return evaluate(v1) > evaluate(v2);
	}
	
	protected static int evaluate(String s){
		char v = s.charAt(s.length()-1);
		switch(v){
		case '(' : return 2; 
		case '+' :
		case '-' : return 4; 
		case '*' :
		case '/' : return 8;
		default : return 100;
		}
	}

	
	public static boolean isOperand(String v){
		String regex_fig = "^(?:[\\+\\-]?[1-9]\\d*|0)(?:\\.\\d+)?$"; 
		Pattern p_fig = Pattern.compile(regex_fig);
		Matcher m =  p_fig.matcher(v);
		boolean b = m.matches();
		return b;
	}


}