Apr 12, 2021 · One way to silence this warning in particular without replacing it with _ or removing it is to explicitly use and discard it. For example: If you want to disable all warnings, you can pass the -suppress-warnings flag (or turn on "Suppress Warnings" under "Swift Compiler - Warning Policies" in Xcode build settings).

If you need to use the value inside of a variable, declare it with a name and not _. The underscore says, I know this call returns a value but we're not going to use it, so it doesn't need a name. Swift emits warnings for unused function call results, so this is a way to suppress that warning.

Apr 9, 2021 · It offers an optional `mutable_variant` for when an expected return value is not consumed. For example, when `sort` is called with an unused result, the compiler suggests using `sortInPlace` for unused results. ```swift @warn_unused_result(mutable_variant="sortInPlace") public func sort() -> [Self.Generator.Element] ```

If I'm just typing a variable out like: var someURLs = Array<URL>() I get a compiler warning, with a suggestion that will change the code to: _ = Array<URL>() I just typed it out, I'm about to use the variable in a couple of seconds, so I really don't want to use the suggested fix.

Jul 19, 2018 · Swift warns on unused local variables but not function parameters. I use SwiftLint to catch those, along with other unused cases like closure captures.

Every useful program needs to store data at some point, and in Swift there are two ways to do it: variables and constants. A variable is a data store that can have its value changed whenever you want, and a constant is a data store that you set once and can never change.

Jan 12, 2025 · Here’s how you declare variables and constants in Swift: Variables: Use the var keyword. Constants: Use the let keyword. // Declaring a variable var message = "Hello, world!" print (message) // Output: Hello, world!

Use Swift variables to store and manage changing data. Learn how to declare, modify, and use variables in functions, loops, and structures.

Dec 26, 2023 · Swift encourages you to use constants (let) wherever the value doesn't need to be changed. This practice enhances safety by preventing inadvertent value modification. Variables (var), on the other hand, should be used for values that may need to be altered.

Prefer constants over variables when the value won't change; Use type inference when possible, but explicitly declare types when needed for clarity; Consider using optionals when a variable might not have a value; Understanding variables and constants is …