Swift - Decision Statements

In programming, decision statements are used to determine the flow of execution of a program based on certain conditions or criteria. In Swift, there are three types of decision statements: if statements, switch statements, and guard statements.

If Statements

If statements in Swift are used to execute code only if a certain condition is met. The basic syntax of an if statement is as follows:

if condition {
    // code to execute if condition is true
}

If the condition is true, the code inside the curly braces will be executed. If the condition is false, the code will be skipped. If you want to execute a different block of code when the condition is false, you can use an else statement:

if condition {
    // code to execute if condition is true
} else {
    // code to execute if condition is false
}

You can also chain multiple conditions together using else if statements:

if condition1 {
    // code to execute if condition1 is true
} else if condition2 {
    // code to execute if condition2 is true and condition1 is false
} else {
    // code to execute if both condition1 and condition2 are false
}

Switch Statements

Switch statements in Swift are used to execute different blocks of code depending on the value of a variable or expression. The basic syntax of a switch statement is as follows:

switch value {
case option1:
    // code to execute if value equals option1
case option2:
    // code to execute if value equals option2
default:
    // code to execute if value does not match any of the options
}

The value can be any data type that can be compared using the == operator, such as numbers, strings, or enums. The options must be a value that matches the data type of the value being switched on. The default case will be executed if none of the other cases match.

Guard Statements

Guard statements in Swift are used to exit a function, loop, or code block early if a certain condition is not met. The basic syntax of a guard statement is as follows:

guard condition else {
    // code to execute if condition is false
    return
}

If the condition is true, the code after the guard statement will be executed. If the condition is false, the code inside the else block will be executed and the function, loop, or code block will be exited using the return statement. This is useful for avoiding nested if statements and improving code readability.

In conclusion, Swift provides us with three types of decision statements – if, switch, and guard statements. Each of them is useful in different scenarios to make our code more efficient, concise, and readable.