Can you explain the intention behind using the `(function(): Something{})` syntax?

(function() : Contract {}).

The code looked like an IIFE but then there was a colon, not what I expected. Was it meant to be a label?

https://i.sstatic.net/wBYAT.png

Answer №1

When using TypeScript, it's important to note that the syntax differs from JavaScript. The presence of a colon indicates that the function will return a value of type Contract.

For instance:

const foo = (function(): Foo {
  // lots of code
  return someExpression;
})();

In this example, TypeScript would require that someExpression is of type Foo.

While specifying the return type in TypeScript functions is common practice, it is not always necessary. Omitting it allows TypeScript to infer the type automatically, reducing unnecessary syntax clutter.

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