使用new运算符的String对象数 [英] How many String objects using new operator
问题描述
当我们使用new运算符创建一个String对象时,我读到创建了两个对象,一个Object是字符串常量池,第二个是堆内存。
When we use new operator to create a String object, I read that two Objects are created one Object is string constant pool and second one is in heap memory.
我的问题是我们正在使用new运算符,因此只应在Heap中创建一个对象。为什么然后必须在String Constant池中创建另外一个对象。我知道只要我们不使用new运算符来创建String,Java就会存储String对象。例如:
My question here is We are using new operator hence only one object should be created in Heap. Why then one more object has to be created in String Constant pool. I know Java stores String object whenever we not use new operator to create a String. For eg:
String s = "abc" .
在这种情况下,它只会在String常量池中创建。
In this case only it will create in String constant pool.
String s2 = new String("abc")
只有一个对象可以在堆中创建,而不是在常量池中。
only one object hast to be created in heap and not in Constant pool.
请解释我为什么错在这里。
Please explain why I am wrong here.
推荐答案
我们正在使用new运算符,因此只应在堆中创建一个对象。
We are using new operator hence only one object should be created in Heap.
当然 - new
操作只创建一个对象。但它的参数是一个String文字,它已经代表了一个对象。每次使用String文字时,都会在类加载期间为其创建一个对象(除非在其他地方已经使用了相同的文字)。这不会被跳过,因为您之后使用该对象作为 new String()
操作的参数。
Sure - the new
operation only creates one object. But its parameter is a String literal, which already represents an object. Any time you use a String literal, an object was created for that during class loading (unless the same literal was already used elsewhere). This isn't skipped just because you then use the object as a parameter for a new String()
operation.
正因为如此,新的String()
操作在大多数情况下是不必要的,很少使用。
And because of that, the new String()
operation is unnecessary most of the time and rarely used.
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