java while loop example

1. How to jump out of the current multi-nested loop in java? In java, if you want to jump out of multiple nested loops, you can define a label before the loop statement, and then use the break statement with the label in the code in the loop body to jump out of the outer

1 , JAVA Performance Tuning-do not use expressions in loop conditionsWhen we learn about Java Performance Tuning, we often see this passage: In the case of No compilation optimization, in the loop, the loop condition will be repeatedly calculated, if you do not use complex e

For loopThe number of times the For loop executes is determined before execution. The syntax format is as follows: for (initialize; Boolean expression; update) {// code statement }There are several explanations for the For loop: The initialization step is performed first. You can declare a type, but you can initialize one or more loop control variables,

The FOR Loop statement is a very useful looping statement in Java programming. A For loop can be used to repeatedly execute a statement until a condition is satisfied. The addition of the enhanced foreach syntax in Java 5 is also very useful.1. For statementThe number of times the For

The For-each loop is also called an enhanced for loop, or a foreach loop.The For-each loop is a new feature of JDK5.0 (other new features such as generics, auto-boxing, etc.).The addition of the For-each loop simplifies the traversal of the collection.Its syntax is as follows:for (type Element:array){SYSTEM.OUT.PRINTLN

The Java language does not provide a goto statement to control the jump, which improves the readability of program flow control, but reduces the flexibility of programmatic controls. To compensate for this deficiency, Java provides continue and break to control the loop structure, and in addition, return can end the entire method and end a

instructions and flowchart: 1. perform the loop body first2. post-judgment Boolean expression3. The loop body is executed at least onceDo-while Loop Code: Package com.oliver.test; Public class Dowhile { publicstaticvoid main (string[] args) { int i = 1; Do { = i+1; I++ ; } while (i); System.out

Java enhanced for LoopJava5 introduces an enhanced for loop that is primarily used for arrays . The Java enhanced for loop syntax format is as follows :( in simple terms, the elements in the array are sequentially output )for ( declaration statement : expression ){code sentences}declaration statement: declares a n

In practical programming, it is sometimes necessary to jump out of a loop when a conditional statement is matched. In Java, it is controlled by the break and continue statements."Break" statementThe "break" statement is used to end the loop, that is, all loops behind it are no longer executed.Example: Calculate the result of a 1+2+3+4......+100.public class examp

Use the FOR Loop statement to output the following funnel effect:+------+|\..../|| \.. / || \/ || /\ || /.. \ || /....\|+------+Code: (See the code header for more lines of comment)In this example code, a constant height is used, which refers to half of the interior height value of the funnel as a constant value./** +------+ height:3 * |\..../| First line: Number of spaces: 0 Pips: 4 spaces: 0 * | \..

The java1.5 version introduces an enhanced for loop, which is similar in principle to for loops.Syntax declaration: for (expression: conditional expression)Example: For(String str: set) Explanation: Set represents the set set, and STR represents the type stored in the set set.The code examples are as follows:Set New Hashset(); Iteratorset while (It.hasnext ()) { = It.next (); System. out forset) {

enhanced for loopInt[] arr = {A-i};for (int num:arr) {num= 0;}System.out.println (arr[1]);Publicclass Demo3 {@Testpublic void Test3 () {Map map=new HashMap ();Map map2=newlinkedhashmapMap.put ("1", "AAA");Map.put ("2", "BBB");Map.put ("3", "CCC");Traditional Way 1Set Set=map.keyset ();Iterator It=set.iterator ();while (It.hasnext ()) {stringkey= (String) it.next ();Stringvalue= (String) map.get (key);System.out.println ("key=" +key+ ", value=" +value);}Traditional Way 2Set Set2=map.entryset ();

1.breakBreak is used to completely end a loop and jump out of the loop body. Regardless of the loop, once a break is encountered in the loop body, the system will completely end the loopIn Java is the label definition, the tag is a colon immediately following the English (:)

Complete the same function, with different code to achieve, there may be a large difference in performance, so for some performance-sensitive modules, it is necessary to optimize the code. Today, let's talk about Java code optimization, and today we're going to focus on optimizations for the for (while and so on) loops.As one of the three major structures of the cycle, we are often used when writing code. The loop