answersLogoWhite

0

The golden rule in iteration: everything done with a for loop can be done with a while loop, BUT not all while loops can be implemented with a for loop. for-loops are just a short-cut way for writing a while loop, while an initialization statement, control statement (when to stop), and a iteration statement (what to do with the controlling factor after each iteration). = Examples of for-loops = The most basic use for using for-loops is to do something a set number of times: for(int k = 0; k < 10; k++); // this loops runs for 10 times another less common use of the for-loop is traversing raw listNodes, since it does contain an initialization(finding the first node), control (as long as there is a next node), and a iteration statement (get my next node). i.e.: for(ListNode temp = startingNode; temp != null; temp = temp.getNext); // this traverses the entire ListNode list and stops when it has exhausted the list = How to implement for-loops using while loop = Basically for loops are just short hand for while loops, any for loop can be converted from: for([initialize]; [control statement]; [iteration]); to [initialize]; while([control statement]) { //Do something [iteration]; } These two does the exact same thing. = For When Only while Loop can be used = while-loops are used when the exiting condition has nothing to do with the number of loops or a controll variable, maybe you just want to keep prompting the user for an input until the given input is valid, like the following example which demands a positive number: int x = [grab input]; while(x < 0) { // Do code

x = [grab input];

} It is true that, when used as intended, a for loop cannot do everything a while loop can, however, in reality, for loops are just as versatile. For example, the above while loop can easily be rewritten to be a for loop as so:

for(int x = [grab input]; x < 0; x = [grab input]){

// Do Code

}

The above for loop behaves exactly like the while loop in the previous heading. A better example of a while loop that should not be a for loop might be:

while(true){

// Do some processing

// Check some condition. If condition is met, break out of loop.

// Do some more processing.

}

Here, the checking of the condition comes in the middle of the processing for the while loop, whereas the condition checked in a for loop is always done at the beginning of the loop. Also, the "iteration" statement is non-existant and is a factor of processing done somewhere else in the while loop. Finally, there was no initialization for this while loop. However, this while loop can still be written as a for loop:

for(;true;){

// Do some processing

// Check some condition. If condition is met, break out of loop.

// Do some more processing.

}

As you can see, a for loop is exactly like a while loop if you leave out the initialization and iteration sections (you still needs the semicolons, to signify those parts of the for loop are still there, they just do nothing). However, it is clear that when you do not need the extra portions of the for loop, why not just use a while loop?

The basic for loop was extended in Java 5 to make iterating over arrays and other collections more convenient. See this website for further explanation:

(http://www.leepoint.net/notes-java/flow/loops/foreach.html)

User Avatar

Wiki User

16y ago

What else can I help you with?

Related Questions

In semaphore technique instead of while loop why for loop is used over there also what is the reason behind that ref-given in silberschatz of operating system concepts sixth edition book?

You should ask Silberschatz himself about that.


Which pair of loops causes a statement or set of statements to repeat as long as a condition is true?

A while loop repeats until the condition becomes false, and may never execute: int a = 4; while (a &gt; 5) { //Do something } or int a = 4; while (a &gt; 0) { //Do something a--; }


Which loop is used in php?

while, do...while, for, foreach are used


When should use a while loop over a do loop?

Generally speaking a for loop looks like this:for(Initialization;condition;increment){Do Stuff}whereas a while loop looks like this:while(condition){Do Stuff}Before the while loop there should be some initialization and somewhere in the Do Stuff section there should be statements that change the condition. Those statements are analogous to the increment section of the for loop.


What are control structures used in javascript?

The control structures used in java script are if-statement, for-loop, for-in loop, while loop,do-while loop, switch-statement, with-statement. try-catch-finally statements.


What is used to end a do loop?

A while statement.


What is while statement and how is it used?

You use a while statement to introduce a conditional loop. Unlike a for loop which is typically used for counted loops, a while loop is used whenever a statement must iterate while an expression evaluates true. The expression is evaluated at the start of each iteration.


What kind of loop is used to perform the loop until a special value is entered?

while


What is the significance of test condition in a loop?

The test condition in a loop is what's used to determine when the loop should end.


What are the types of loops?

There are three forms of loop commonly used in C/C++, the for loop, the while loop and the do-while loop. The for loop is most commonly used whenever an action is going to be performed a set amount of times. For example, to sum every element in an array: for(i = 0; i &lt; arraySize; i++) { sum = sum + array[i]; } The while loop and do-while loop are commonly used to loop until a condition is met. The difference between the two is that the do-while loop goes through one iteration before checking its condition, while the while loop checks its condition before any execution of the loop. Example do-while loop: do { randomNumber = rand() % 10; }while(randomNumber != 6); Example while loop: cout &gt; number; while(number &lt; 0) { cout &gt; number; }


What is the difference between while and for loop in c programming?

when use for loop user can assign the value of the variable inside the loop, while checking the condition. but in while loop he has to assign it out side of the loop. like for loop: for(i=5, n=2; i&lt;=8; i++) { n=n+5; } while loop: int i=5, n=2; while(i&lt;=8) { n=n+5; i++; }


What is the difference between a for loop and a while loop in java?

ComparisonThe conditions for both the 'while' and 'for' loop are exactly the same, but in each flow structure the conditions are placed in different locations. A 'for' loop places the full condition within the 'for' loop whereas the 'while' loop places the counter variable outside of the loop.The 'for' loop is used when the length of the loop is known whereas the 'while' loop is usually used when the length of the loop is unknown.'for' loop exampleWithin the parentheses the complete condition is contained. The condition has 3 parts delimited by a colon ';'. The first part sets the counter 'int i' to 0, the second part tells the loop to stop when the counter is 5. The third part tells java to increment the counter by 1 value each time the loop iterates.for ( int i = 0; i < 5; i++)'while' loop exampleWith the 'while' loop the counter is initialized outside of the 'while' loop. Inside the parentheses of the loop the condition is set to stop looping when the counter reaches a value of 5. Inside of the 'while' loop block the counter is set to increment by 1 value each time the loop iterates.int i = 0;while ( i < 5 ) {i++}