Swift If Else Statements

Examples

Example 1: if Statement

Code:

let number = 10

// check if number is greater than 0
if (number > 0) {
  print("Number is positive.")
}

print("The statement is easy.")

Output:

Number is positive.
The statement is easy.

In the preceding example, we defined a variable called number. Take note of the test condition,

number > 0

Because the number is greater than zero, in this case, the condition is true.

If the variable is changed to a negative integer. Let's say it's -1.

let number = -1

When we run the programme now, the output will be as follows:

The statement is easy.

This is due to the fact that the value of a number is less than 0. As a result, the condition evaluates to false. The body of the if block is also skipped.

Example 2: If-else Statement

Code:

let number = 5

if (number > 0) {
    print("Positive Number.")
}
else {
    print("Negative Number.")
}
print("This statement is always executed.")

Output:

Positive Number.
This statement is always executed.

Example 3: Swift if-else if Statement

Code:

// check if a number is positive, negative, or 0.

let number = 5

if (number > 0) {
    print("Positive Number.")
}

else if (number < 0) {
    print("Negative Number")
}

else {
    print("Number is 0.")
}

print("This statement is always executed")
 

Output:

Positive Number.

In the preceding example, we created a variable called a number with the value 0. We have two condition expressions here:

if (number > 0) - determines whether or not the number is greater than zero. if (number 0) - determines whether the number is less than zero.

In this case, both conditions evaluate as false. As a result, the statement within the body of else is executed.

Example 4: Nested if-else Statement

Code:

var number = 0
// outer if statement
if (number >= 0) {
  // inner if statement
  if (number == 0) {
      print("Number is 0")
  }
  // inner else statement
  else {
      print("Positive Number");
  }
}
// outer else statement
else {
    print("Negative Number");
}

Output:

Number is 0

In the preceding example, we used a nested if statement to determine whether the given number was positive, negative, or zero.

Check out this problem - First Missing Positive 

Frequently Asked Questions

What is the meaning of if-else? 

You can make a chain of if statements using the if/else if statement. The if statements are assessed one by one until one of them if expressions are true or the if/else if chain ends. There are no code blocks run if the if/else if chain reaches the end without a true statement.

What is a nested if-else example?

First, we check that out of the three numbers, the first two are equal. If they are, then we go inside the nested if to check whether the third is equal to them. If yes, then all are equal else they are not equal.

Does else have to follow ‘if’?

Only the if (expression) statement and the else statement are present. Because an if statement is a statement, you can use it after else just like any other statement, such as for or empty; or switch or any other arbitrary expression statement.

Conclusion

In this blog, we have extensively discussed the Swift If-else Statements. We hope that this article has provided you with additional information about the If-else statements in swift. And to learn in-depth about Android, check out the course on Android on the Coding Ninjas website. And also, check out the awesome content on the Coding Ninjas Website, Android Development, Coding Ninjas Studio Problems, Coding Ninjas Studio Interview Bundle, Coding Ninjas Studio Interview Experiences, and Coding Ninjas Courses, Coding Ninjas Studio Contests, and Coding Ninjas Studio Test Series. Do upvote our blog in helping other ninjas grow.
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