12. The following results show how much code execution ()?

The following results show how much code execution ()?

A.true,false,true

B.false,true,false

C.true,true,false

D.false,false,true

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In fact, when we assigned to Integer, java compiler will translate into calls valueOf () method. For example Integer i = 127 is translated Integer i = Integer.valueOf (127)

Then we take a look at the source valueOf () function:

public static Integer valueOf(int i)

    {

        //high为127

        if(i >= -128 && i <= IntegerCache.high)

            return IntegerCache.cache[i + 128];

        else

            return new Integer(i);

    }

As can be seen, for a number between -128 to 127, Java will be cached. And beyond that is to create a new object.

So now back to this problem Road

i1 and i2 128, out of range, so the need to create a new object, the object comparison is false;

100 i5 and i6, within range, when executed Integer i5 = 100, is cached in memory directly, but execution Integer i6 = 100, it is taken directly from the cache, without the need to create a new object, It is true.