66 lines
1.7 KiB
Markdown
66 lines
1.7 KiB
Markdown
|
---
|
||
|
|
title: Infinite Loops
|
||
|
|
---
|
||
|
|
# Infinite Loops
|
||
|
|
|
||
|
|
An infinte loop is a loop statement (`for`, `while`, `do-while`) which does not end on its own.
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
|
||
|
|
```java
|
||
|
|
// Infinite For Loop
|
||
|
|
for ( ; ; )
|
||
|
|
{
|
||
|
|
// some code here
|
||
|
|
}
|
||
|
|
|
||
|
|
// Infinite While Loop
|
||
|
|
while (true)
|
||
|
|
{
|
||
|
|
// some code here
|
||
|
|
}
|
||
|
|
|
||
|
|
// Infinite Do While Loop
|
||
|
|
do
|
||
|
|
{
|
||
|
|
// some code here
|
||
|
|
} while (true);
|
||
|
|
```
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
```java
|
||
|
|
for(int i=0;i<100;i++){
|
||
|
|
|
||
|
|
if(i==49){
|
||
|
|
i=0;
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
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'.
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
```java
|
||
|
|
while (true)
|
||
|
|
{
|
||
|
|
// do something
|
||
|
|
|
||
|
|
if(conditionToEndLoop == true)
|
||
|
|
break;
|
||
|
|
|
||
|
|
// do more
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
The main advantage of using an infinite loop over a regular loop is readability.
|
||
|
|
|
||
|
|
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.
|
||
|
|
|