Here you can find the source of toDouble(String s)
public static double toDouble(String s)
//package com.java2s; public class Main { public static double toDouble(String s) { if ((s != null) && (!("".equals(s.trim())))) return Double.parseDouble(s); return 0.0D; }/*from w w w . ja v a2 s. co m*/ public static boolean equals(String s1, String s2) { if ((isEmpty(s1)) && (isEmpty(s2))) return true; if ((!(isEmpty(s1))) && (!(isEmpty(s2)))) return s1.equals(s2); return false; } public static boolean isEmpty(String s) { return ((s == null) || ("".equals(s))); } public static String isEmpty(String s, String result) { if ((s != null) && (!(s.equals("")))) return s; return result; } }