IFSTATEMENTS

Conditional Statements in Vint

Conditional statements in Vint allow you to perform different actions based on specific conditions. The if/else structure is fundamental for controlling the flow of your code. Here's a simple guide to using conditional statements in Vint.

If Statement (if)

The if statement checks a condition inside parentheses (). If the condition evaluates to true, the code block inside curly braces {} will execute:

if (2 > 1) {
    print(true)  // Output: true
}

In this example, the condition 2 > 1 is true, so print(true) is executed, and the output is true.

Else If and Else Blocks (else if and else)

You can use else if to test additional conditions after an if statement. The else block specifies code to execute if none of the previous conditions are met:

let a = 10

if (a > 100) {
    print("a is greater than 100")
} else if (a < 10) {
    print("a is less than 10")
} else {
    print("The value of a is", a)
}

// Output: The value of a is 10

Explanation:

1. The condition a > 100 is false.
2. The next condition a < 10 is also false.
3. Therefore, the else block is executed, and the output is The value of a is 10.

Summary

• if: Executes code if the condition is true.
• else if: Tests another condition if the previous if condition is false.
• else: Executes code if none of the above conditions are true.

By using if, else if, and else, you can make decisions and control the flow of your Vint programs based on dynamic conditions.

If Statements and If Expressions in Vint

Vint supports both classic if statements and the new if expressions, allowing you to use conditional logic in both statement and expression positions.

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Classic If Statement

The classic if statement executes a block of code if a condition is true. You can optionally provide an else block.

Syntax:

if (condition) {
    // code to run if condition is true
} else {
    // code to run if condition is false
}

Example:

let x = 0
if (true) {
    x = 42
}
print("Classic if statement result: ", x)

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If as an Expression (New Feature)

You can now use if as an expression, which returns a value. This allows you to assign the result of a conditional directly to a variable, or use it in any expression context.

Syntax:

let result = if (condition) { valueIfTrue } else { valueIfFalse }

• The if expression evaluates to the value of the first block if the condition is true, or the value of the else block if provided.
• If the condition is false and there is no else, the result is null.

Examples:

let status = ""
status = if (x > 0) { "Online" } else { "Offline" }
print("If as an expression result: ", status)

let y = if (false) { 123 }
print("If as an expression with no else: ", y) // prints: null

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Notes

• Parentheses around the condition are required: if (condition) { ... }.
• Both the classic statement and the new expression form are fully supported and can be mixed in your code.
• Use // for single-line comments and /* ... */ for multi-line comments in Vint.

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See Also

• Switch Statements
• Operators