Final answer:
The main difference is that a nested IF statement is an IF statement within another IF, enabling the testing of multiple, hierarchically structured conditions. A regular IF statement can stand alone and evaluate a single condition or multiple conditions combined with logical operators. Option 2 in the given choices is the most accurate description of this difference.
Step-by-step explanation:
The primary difference between a nested IF statement and an IF statement is that a nested IF statement refers to an IF statement inside another IF statement, which allows for testing multiple conditions and creating complex decision structures. However, an IF statement can exist independently and typically evaluates a single condition. Option 2 correctly states that the nested IF statement can only be used inside another IF statement, while the IF statement can be utilized on its own.
Option 1 is incorrect because a single IF statement can also evaluate multiple conditions using logical operators like AND, OR, etc. Option 3 is incorrect because nesting IF statements does not necessarily make them more efficient; it can actually make the code more complex and harder to read. Option 4 is only partially correct because while nested IFs do allow for more complex operations, even a single IF statement can perform complex comparisons with appropriate logical operators.
When using nested IF statements, it's important to manage the complexity to ensure the code remains readable and maintainable. For example, if we wanted to check if a number is positive, greater than 50, and even, we could use a nested IF statement like so:
if (number > 0) {
if (number > 50) {
if (number % 2 == 0) {
// Code to execute if all the conditions are true
}
}
}
As you can see, each condition is checked in a stepwise manner, and only if the preceding condition is true does the next condition get evaluated.