Integer

最新推荐文章于 2024-10-10 20:46:49 发布

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最新推荐文章于 2024-10-10 20:46:49 发布

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原文链接：http://www.cnblogs.com/ukouryou/articles/3254589.html

samples:

Integer x = 500;
Integer y = 500;
System.out.println(x == y + 0); //true
System.out.println(x == y); //false

Integer x = 127;
Integer y = 127;
System.out.println(x == y + 0); //true
System.out.println(x == y); //true

1.Integer + int :autounboxing

This is equivalent to :Integer.intValue() + int

2. Because of this code in Integer

1 public static Integer valueOf(int i) {
2         if(i >= -128 && i <= IntegerCache.high)
3             return IntegerCache.cache[i + 128];
4         else
5             return new Integer(i);
6     }

View Code

Explanation:

Integer integer1 = 127 is a shortcut for Integer integer1 = Integer.valueOf(127), and for values between -128 and 127 (inclusive), the Integers are put in a cache and returned multiple times, while higher and lower numbers generate new Integers each time.

转载于:https://www.cnblogs.com/ukouryou/articles/3254589.html