What this snippet does
Direct annotation widens the inferred type of 'a' to the union, whereas satisfies would preserve it as the literal 1.
Expected output
number
Why practise typing this
Typing modern typescript code builds muscle memory for the symbols and indentation TypeScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More TypeScript practice
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- Declaring variables with primitive typesBasic Types · beginner
- Typing function parameters with primitivesBasic Types · beginner
- Assigning a string to a number variableBasic Types · beginner
- Defining an array of numbersBasic Types · beginner