Javascript Developer JSE 40 01 · Free Practice Question Medium
Question 9
Q122 - Control Flow
Which of the following loop instructions checks
the loop continuation condition only after the iteration has been completed?
-
A
while -
B
for ... in -
C
do ... while -
D
for
Reveal correct answer
Correct answer: C
Explanation
Topic: do while
Try it yourself:
- let dice;
- do {
- dice = Math.floor(Math.random() * 6) + 1;
- console.log(dice)
- } while (dice != 6);
Explanation:
The do while is used when you want to run a code block at least one time.
https://www.w3schools.com/jsref/jsref_dowhile.asp
Q122 (Please refer to this number, if you want to write me about this question.)
A. The while loop in JavaScript checks the loop continuation condition before each iteration, not after the iteration has been completed. It is used when the number of iterations is not known beforehand, and the loop will continue as long as the condition is true.
B. The for...in loop in JavaScript is used for iterating over the properties of an object. It does not check the loop continuation condition after the iteration has been completed; instead, it iterates over the enumerable properties of an object.
C. The do...while loop in JavaScript is unique in that it checks the loop continuation condition after the iteration has been completed. This means that the loop body will always execute at least once before the condition is checked for continuation.
D. The for loop in JavaScript checks the loop continuation condition before each iteration, not after the iteration has been completed. This loop structure is commonly used for iterating over a range of values or elements in an array.
Discussion
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