Equalと==
1502 ワード
package day20161009;
public class EqualTest
{
public static void main(String[] args)
{
int it = 65;
float fl = 65.0f;
System.out.println("65 65.0f ?" + (it == fl));
char ch = 'A';
System.out.println("65 'A' ?" + (it == ch));
String str1 = new String("hello");
String str2 = new String("hello");
String a = "abc";
String b = "abc";
System.out.println("a b ?"+(a == b));
System.out.println("str1 str2 ?"
+ (str1 == str2));
System.out.println("str1 equals str2?"
+ (str1.equals(str2)));
// s1 " "
String s1 = " ";
String s2 = " ";
String s3 = " ";
// s4
// s4 " "
String s4 = " " + " ";
// s5
// s5 " "
String s5 = " " + " " + " ";
// s6 ,
//
String s6 = s2 + s3;
// new String ,
// s7 String
String s7 = new String(" ");
System.out.println(s1 == s4); // true
System.out.println(s1 == s5); // true
System.out.println(s1 == s6); // false
System.out.println(s1 == s7); // false
}
}
/*65 65.0f ?true
65 'A' ?true
a b ?true
str1 str2 ?false
str1 equals str2?true
true
true
false
false*/
http://cakin24.iteye.com/blog/2329004