ea5480a2c4
Some of the uses of an infinite loop just to suggest that the use of an infinite loop is not always an error
90 lines
2.5 KiB
Markdown
90 lines
2.5 KiB
Markdown
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title: Infinite Loops
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---
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# Infinite Loops
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An infinte loop is a loop statement (`for`, `while`, `do-while`) which does not end on its own.
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The test condition of a looping statement decides whether the loop body will execute or not. So a test condition which is always true will keep on executing the body of the loop, forever. That's the case in an infinte loop.
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Examples:
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```java
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// Infinite For Loop
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for ( ; ; )
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{
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// some code here
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}
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// Infinite While Loop
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while (true)
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{
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// some code here
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}
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// Infinite Do While Loop
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do
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{
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// some code here
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} while (true);
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```
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Normally, if your loop is running infinitely, it is an error that should not occur as an infinite loop does not stop and prevents the rest of the program from running.
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```java
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for(int i=0;i<100;i++){
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if(i==49){
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i=0;
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}
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}
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```
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The loop above runs infinitely because every time i approaches 49, it is set to be 0.This is to say that i never reaches 100 to terminate the loop, so the loop is an infinite loop.
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But a program stuck in such a loop will keep using computer resources indefinitely. This is undesirable, and is a type of 'run-time error'.
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#### Infinite Loop by opposite iteration
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Another example of an Infinite Loop can be seen below:
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```java
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for(int i=0;i<=10;i--)
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System.out.println(i);
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```
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In the above example, the initial value of `i` is 0. Since value of `i` is less than equal to 10, we decrement the value of `i` by 1, so `i` will now be -1. Hence, the loop will be infinite.
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Similarly, an example of an infinite while loop example can be seen below:
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```java
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int i=1;
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while(i>=1)
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{
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System.out.println(i);
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i+=1;
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}
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```
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Here, `i` will always be greater than 1, so the program will be in an infinite loop.
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To prevent the error, programmers use a `break` statement to break out of the loop. The `break` executes only under a particular condition. Use of a selection statement like `if-else` ensures the same.
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```java
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while (true)
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{
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// do something
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if(conditionToEndLoop == true)
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break;
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// do more
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}
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```
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The main advantage of using an infinite loop over a regular loop is readability.
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Sometimes, the body of a loop is easier to understand if the loop ends in the middle, and not at the end/beginning. In such a situation, an infinite loop will be a better choice.
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Uses: A lot of programs (embedded control software, graphical applications, games, web & DBMS servers, and even Unix or Posix or Linux kernels) is organized around an infinite event loop. Servers also listen to incoming traffic in an endless loop.
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