What this snippet does
super() must be called in a child constructor before accessing this — it runs the parent's constructor.
Expected output
Rex barks. Whiskers meows. true
Why practise typing this
Typing classes code builds muscle memory for the symbols and indentation JavaScript 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 JavaScript practice
- class syntaxClasses · beginner
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- abstract methodsClasses · advanced
- mixinsClasses · advanced