string-pool

问题 Is there any way to check, currently which Strings are there in the String pool. Can I programmatically list all Strings exist in pool? or Any IDE already have this kind of plugins ? 回答1: You are not able to access the string pool from Java code, at least not in the HotSpot implementation of Java VM. String pool in Java is implemented using string interning. According to JLS §3.10.5: a string literal always refers to the same instance of class String . This is because string literals - or,

问题 Having the following code: String s="JAVA"; for(i=0; i<=100; i++) s=s+"JVM"; How many Strings are created? My guess is that 103 Strings are created: 1: the String "JAVA" in the String pool 1: the String "JVM" also in the String pool 101: the new String s is created every time in the loop because the String is an Immutable class 回答1: String concatenation is implemented through the StringBuilder (or StringBuffer ) class and its append method. String conversions are implemented through the

问题 Beware: I'm not trying to compare if the characters are equals. Because I know how to use the String.equals() method. This question is about String reference I was studying for the OCA exam when I started to learn about the class String and it properties as immutability, etc. According to what I read or may understand about String pool is that when a string is created Java stores this object on what they call String pool and if a new string is created with the same value it is going to make

问题 I have been reading Java String object and I had this question - String x="a"; String y="b"; Does it create two objects in Java? 回答1: Those two lines of code will not create any objects. String literals such as "a" are put in the string pool and made available upon class loading. If you do String x = new String("a"); String y = new String("b"); two objects will be created in runtime. These questions/answers should cover follow-up questions: Questions about Java's String pool How many Java

问题 I need a "string pool" object into which I can repeatedly insert a "sequence of chars" (I use this phrase to mean "string" without confusing it with std::string or a C string), obtain a pointer to the sequence, and be guaranteed that the pointer will not become invalidated if/when the pool needs to grow. Using a simple std::string as the pool won't work, because of the possibility for the string to be reallocated when it outgrows its initial capacity, thus invalidating all previous pointers

问题 just been inspecting the following in gdb: char *a[] = {"one","two","three","four"}; char *b[] = {"one","two","three","four"}; char *c[] = {"two","three","four","five"}; char *d[] = {"one","three","four","six"}; and i get the following: (gdb) p a $17 = {0x80961a4 "one", 0x80961a8 "two", 0x80961ac "three", 0x80961b2 "four"} (gdb) p b $18 = {0x80961a4 "one", 0x80961a8 "two", 0x80961ac "three", 0x80961b2 "four"} (gdb) p c $19 = {0x80961a8 "two", 0x80961ac "three", 0x80961b2 "four", 0x80961b7

问题 If I run, String s1="abc"; then are there any differences between: String s2=new String(s1); and String s2="abc"; Here's what I'm confused about: The Head First Java says:"If there's already a String in the String pool with the same value, the JVM doesn't create a duplicate, it simply refers your reference variable to the existing entry. " Which at my point of view is that the s1 has already created "abc",s2 just refers to it. Am I right?? 回答1: When you write String s2="abc"; and "abc" is

问题 This question already has answers here : What is the Java string pool and how is “s” different from new String(“s”)? [duplicate] (5 answers) Closed 5 years ago . If for example: String str1 = “abc”; String str2 = new String(“def”); Then, Case 1 : String str3 = str1.concat(str2) will go in the heap or pool? Case 2 : String str4 = str2.concat(“HI”) will go in the heap or pool? 回答1: In java, whichever String u create using new keyword will be created in heap memory. If you create any String

问题 I read many answers but none of them really answers my question exactly. If I've a java service running on some port and a client connects to it and calls a method like: String data = getServiceData("clientKey"); Now my question is, will this key(clientKey) be stored in String literal pool on service side? Generally literals to be stored in constant pools are figured out at compile time but what happens to strings that are passed from outside the JVM or may be while reading a file? 回答1: Most

问题 This question already has answers here : When does python choose to intern a string [duplicate] (3 answers) Closed 2 years ago . After seeing this question and its duplicate a question still remained for me. I get what is and == do and why if I run a = "ab" b = "ab" a == b I get True . The question here would be WHY this happens: a = "ab" b = "ab" a is b # Returns True So I did my research and I found this. The answer says Python interpreter uses string pooling. So if it sees that two strings