Difference Between for and while loop
- For loop. The initialization, condition checking, and the iteration statements are written at the beginning of the loop.
- Example
- While condition. The initialization and the condition checking is done at the beginning of the loop. It is used only when the number of iterations isn’t known.
- Example
Which loop is best for or while loop?
Use a for loop when you know the loop should execute ntimes. Use a while loop for reading a file into a variable. Use a while loop when asking for user input. Use a while loop when the increment value is nonstandard. Thanks for reading. If you have a different set of rules for picking between the two, then share them in the comments below.
What is the difference between a for loop and a while loop?
Difference Between For loop and While loop
- The number of iterations in a for loop is predetermined, but in a while loop, this is not the case.
- In contrast, a while loop may include a series of instructions that must be completed sequentially.
- In a for loop, the command is initialized just once, but in a while loop, the command is initialized each time the command is executed.
Why while loop is better than for loop?
While loops will typically only have the same performance or poorer performance than a for loop, but of course it depends on the compiler or interpreter running it. In fact, for loops typically have better performance in compiled languages. Here's why: For loops have an explicit loop counter. That's what you're doing when you set it up:
When to use while loop rather than for loop?
- All loops have 3 components : initialization, condition, updation.
- WHILE LOOP :
- Recognized by keyword ‘while’.
- The condition variable should be already initialized.
- Takes in account only condition part
- Updation is done inside the loop (else, it becomes an infinite loop).
- Syntax :
- while ( condition) { //code with updation (if required) }
- DO-WHILE LOOP :
What is difference between while loop and for loop?
In 'for' loop the initialization once done is never repeated. In while loop if initialization is done during condition checking, then initialization is done each time the loop iterate. In 'for' loop iteration statement is written at top, hence, executes only after all statements in loop are executed.
Which is better while loop or for loop?
In general, you should use a for loop when you know how many times the loop should run. If you want the loop to break based on a condition other than the number of times it runs, you should use a while loop.
Is while same as for loop?
A while loop is slightly different than a for loop for the fact that it's good to use when we don't know how many times we want to loop through a problem beforehand. This is the key difference between using a for loop or a while loop.
Which is faster while or for?
Efficiency, and While vs For Using for: % Time elapsed: 0.0010001659 seconds. Using while: % Time elapsed: 0.026000023 seconds. The main reason that While is much slower is because the while loop checks the condition after each iteration, so if you are going to write this code, just use a for loop instead.
Why is a for loop more powerful than a while loop?
A for loop is more structured than the while loop. The keyword for is used, followed by three statements: initialization: executed before the loop begins. expression: evaluated before each iteration, exits the loop when false.
Do-While VS for loop Java?
If the number of iteration is fixed, it is recommended to use for loop. If the number of iteration is not fixed, it is recommended to use while loop. If the number of iteration is not fixed and you must have to execute the loop at least once, it is recommended to use the do-while loop.
When would you use a while loop?
A "While" Loop is used to repeat a specific block of code an unknown number of times, until a condition is met. For example, if we want to ask a user for a number between 1 and 10, we don't know how many times the user may enter a larger number, so we keep asking "while the number is not between 1 and 10".
When would you use a for loop?
For-loops are typically used when the number of iterations is known before entering the loop. For-loops can be thought of as shorthands for while-loops which increment and test a loop variable.
When to use a while loop?
The 'while' loop used only when the number of iteration are not exactly known. If the condition is not put up in 'for' loop, then loop iterates infinite times. If the condition is not put up in 'while' loop, it provides compilation error. In 'for' loop the initialization once done is never repeated.
What is a do while loop in C++?
In C++ and Java, the iteration statements, for loop, while loop and do-while loop, allow the set of instructions to be repeatedly executed, till the condition is true and terminates as soon as the condition becomes false. Conditions in iteration statements may be predefined as in for loop or open-ended as in while loop.
How often does the initialization statement in a for loop execute?
The initialization statement in the syntax of for loop executes only once at the start of the loop. Conversely, if while loop is carrying initialization statement in its syntax, then the initialization statement in the while loop will execute each time the loop iterates.
What happens if you fail to put condition in for loop?
If you fail to put condition statement in for loop, it will lead to an infinite iteration of a loop. In contrast, if you fail to put condition statement in the while loop it will lead to a compilation error. The initialization statement in the syntax of for loop executes only once at the start of the loop.
What is the condition in a while loop?
The condition in while loop can be any boolean expression. When an expression returns any non-zero value, then the condition is true, and if the expression returns a zero value, the condition becomes false.
Where does the iteration statement execute?
The iteration statement in the for loop will execute after the body for loop executes. On the contrary, the iteration statement can be written anywhere in the body of while loop so, there can be some statements that execute after the execution of iteration statement in the body of while loop.
Do you need curly braces for a while loop?
May it be a for loop or a while loop, if there is only one statement in the body of the loop, the curly braces are not required in that condition.
What is the difference between a for loop and a while loop?
The for loop is quite similar to the while loop in terms of memory consumption and speed. However, the for loop is preferable when you know exactly the number of times the loop has to be repeated. On the contrary, while loop is appropriate when the exact number of iterations is not known, meaning you do not know how many times the loop has to be repeated.
What is a for loop?
What is For Loop? A for loop is an entry control statement used for the repeated execution of certain statements along with the repeated testing for a definite value of expression to be either true or false. The for loop is used for definite loops when the number of iterations are known.
Why do we use loops in programming?
Loops come in extremely handy in situations such as iterating through data structures or traversing through large data sets in order to filter out junk data. When using a loop within a program, you can write one set of instructions that operates on multiple data sets.
Why do we use for loops in C?
For loops are used only to make the code slightly shorter, but also make it easier for other C programmers to read. It seems appropriate when the initialization and increment are logically related and are single statements.
When is a for loop preferable?
However, the for loop is preferable when you know exactly the number of times the loop has to be repeated. On the contrary, while loop is appropriate when the exact number of iterations is not known, meaning you do not know how many times the loop has to be repeated.
Can a statement be a block?
Here, statement can be a single or a block of statements. The loop will continue to execute until the condition is true and will terminate once the condition is false.
Can you have a while loop in C?
On the contrary, there is no built-in loop control variable with a while loop . Instead, you can specify any condition that evaluates to either a True or a False value.
Types of loops in Python
In python, we have two different loop statements in order to loop over a piece of code in two different ways. They have the same functionality – i.e., they will execute a certain piece of code only if a condition is met. Yet, they differ in syntax and some other aspects.
The While Loop In Python
The while loop statement is used to repeat a block of code till a condition is fulfilled. When we don’t know the exact number of times, a loop statement has to be executed. We make use of while loops. This way, till the test expression holds true, the loop body will be executed.
The For Loop In Python
The for loop in python is used to iterate over a given sequence. The sequence can be a string, a list, a tuple, a set, a dictionary, etc. As long as the length of the sequence is not reached, it will iterate over that sequence. The for loop contains initialization, the test expression, and the increment/decrement expression in the C language.
For loop vs while loop python
The for loop and while loop are two different approaches to executing the loop statements in python. They both serve the same functionality of looping over a python code till a condition is being fulfilled. For loops and while loops differ in their syntax. In while loops, we have to mention only the condition before starting the loop.
What are loops?
Loops basically allow us to terminate a statement or a group multiple times in a given condition.
While loop
In Python, while loop is basically used to know how many iterations are required.
For loop in Python
In Python, the for loop is used when the user knows the number of iterations that are required. The user knows how many times the statement that is available inside the loops needs to be terminated.
For loop vs while loop in Python
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