2 Kinds of assignment analysis of String class

1. String constant Pool

2. String name = new String ("Hello");

3,String name = "Hello";

Analyze the structure of an object in memory:

Chang--Used to store strings

Hello--is a constant; name--is a variable

Whenever a new object is created, an object is generated in the heap, and the pointer in the stack points to the heap. Hello is a heap of memory stored in the value, will be "hello" this string into the string constant pool to check, see "string constant pool" There is a "hello" constant-if not, will be "hello" this string into the "string constant pool".

string S1 = new String ("Hello");

String s2 = "Hello"; Create at most one string object, possibly without creating an object

In summary, S1 in the new string, first create the object in the heap-"Hello", then, will "hello" to the string constant pool to save again. (The string constant pool is in heap memory)

interview Frequently asked:

string S1 = new String ("Hello"); create several objects?

The answer is: 2-- 1 is in heap memory, and the other is in a constant pool.

1, new 2 created in the heap, "Hello" exists in the string constant pool-for the next time with the same value, will be found from the constant pool.

2, shorthand method has a benefit-will directly let S2 to the constant pool to find, see if there is the same value, there, direct; no, create a "hello" in the constant pool, and then let S2 point to "hello."

2 Kinds of assignment analysis of String class