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TypeScript code kata list

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013 TypeScript - optional parameters

Duration

10 minutes

Brief

Using required, optional, and default parameters. Also an example of interpolation.

For more information

BING/GOOGLE: “TypeScript optional default parameters interpolation”

Instructions

Get tutorial folder or the entire katas-typescript repo.
Open the [before/*.sln] file and execute the kata.
Feel free to execute this kata multiple times because repetition creates motor memory.

Github

• Before (start kata with this)
  
  • https://github.com/robertdunaway/katas-typescript/tree/master/013%20TypeScript%20-%20optional%20parameters/before
• After
  
  • https://github.com/robertdunaway/katas-typescript/tree/master/013%20TypeScript%20-%20optional%20parameters/after

Kata

Create a function that accepts several required parameters and outputs an interpolated string to the console.

    // Create a function that accepts several parameters.
    // These parameters are required by default.
    var profile = function (fName: string, lName: string, age?: number
        , height?: number, weight?: number): string {

        // String interpolation
        console.log(`name: ${fName} ${lName} age: ${age} height: ${height} weight: ${weight}`);

        return '';
    }
    console.log('all parameters are required');
    profile('John', 'Smith', 35, 180, 165);

Create a function with a couple required parameters and a few optional parameters.

    // Create a function where only fName and lName are required and the rest
    // are optional.
    var profileWithOptions = function (fName: string, lName: string, age?: number
        , height?: number, weight?: number): string {

        // String interpolation
        console.log(`name: ${fName} ${lName} age: ${age} height: ${height} weight: ${weight}`);

        return '';
    }
    console.log('example of optional parameters');
    profileWithOptions('John', 'Smith');

Create a function with a couple required parameters and a few default parameters.

    // Create function with default parameters.
    var profileWithDefaults = function (fName: string, lName: string, age: number = 18
        , height: number = 150, weight: number = 100): string {

        // String interpolation
        console.log(`name: ${fName} ${lName} age: ${age} height: ${height} weight: ${weight}`);

        return '';
    }
    console.log('example of default parameters');
    profileWithDefaults('John', 'Smith');
    profile('John', 'Smith', 35, 180, 165);

Next

Take a few minutes and imagine more examples.