Question

3 Quick questions about javascript

1) Operators at the same level of precedence associate(evaluate) from right to left. true or false?

2) The body of a do/while loop is always executed atleast once. True or false?

3) The continue statement allows us to stop and exit the loop immediately. True or false?

Answer 1

1. Operators at the same level of precedence associate (evaluate) from right to left.

Answer: false

In general operator with the highest precedence is evaluated first. When parentheses are used the operations within the parentheses are evaluated first. If the operators are of same level of precedence such as addition and subtraction then the expression is evaluated from left to right.

Example: var a= i + j – k

In the above example + and – have the same precedence, hence first i + j is evaluated and then

(i + j) – k is evaluated.

2. The body of a do/while loop is always executed atleast once.

Answer: True

Unlike the while loop in the do/while loop the body of the loop is executed first and then checks the condition. Hence the body of do-while loop is always executed atleast once.

3. The continue statement allows us to stop and exit the loop immediately.

Answer: False

The continue statement breaks one iteration of the loop when a specified condition is encountered, and continues the loop with the next iteration.

Example:

Suppose i=0

While(i<5)

{

            if(i%2==0)

            {

                        continue;

            }

            document.write("hi ");

            i++;

}

In the above example the loop rum from i = 0 to 5, whenever i is even the loop breaks the current iteration and continues with the next iteration.

Hence the above will write hi hi (when i is 1,3), it does not write hi when i is 0,2,4