muerwre.github.io/api/_content/query/iZIUw8pCoM.json
muerwre 3704dccb33 commit 2bd149f2ce
Author: Fedor Katurov <gotham48@gmail.com>
Date:   Fri Nov 11 16:43:37 2022 +0600

    fixed writing.svg shadows
2022-11-11 10:45:21 +00:00

1 line
No EOL
11 KiB
JSON

{"_path":"/typescript/type-guards","_dir":"typescript","_draft":false,"_partial":false,"_locale":"en","_empty":false,"title":"Type Guards","description":"Useful for type checking at compile and run time:","excerpt":{"type":"root","children":[{"type":"element","tag":"p","props":{},"children":[{"type":"text","value":"Useful for type checking at compile and run time:"}]},{"type":"element","tag":"code","props":{"code":"function isFish(pet: Fish | Bird): pet is Fish {\n return (pet as Fish).swim !== undefined;\n}\n","language":"typescript"},"children":[{"type":"element","tag":"pre","props":{},"children":[{"type":"element","tag":"code","props":{"__ignoreMap":""},"children":[{"type":"text","value":"function isFish(pet: Fish | Bird): pet is Fish {\n return (pet as Fish).swim !== undefined;\n}\n"}]}]}]},{"type":"element","tag":"p","props":{},"children":[{"type":"text","value":"Usage:"}]},{"type":"element","tag":"code","props":{"code":"const pet = getSmallPet();\n \nif (isFish(pet)) {\n pet.swim();\n} else {\n pet.fly();\n}\n","language":"typescript"},"children":[{"type":"element","tag":"pre","props":{},"children":[{"type":"element","tag":"code","props":{"__ignoreMap":""},"children":[{"type":"text","value":"const pet = getSmallPet();\n \nif (isFish(pet)) {\n pet.swim();\n} else {\n pet.fly();\n}\n"}]}]}]}]},"body":{"type":"root","children":[{"type":"element","tag":"p","props":{},"children":[{"type":"text","value":"Useful for type checking at compile and run time:"}]},{"type":"element","tag":"code","props":{"code":"function isFish(pet: Fish | Bird): pet is Fish {\n return (pet as Fish).swim !== undefined;\n}\n","language":"typescript"},"children":[{"type":"element","tag":"pre","props":{},"children":[{"type":"element","tag":"code","props":{"__ignoreMap":""},"children":[{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f71f08"},"children":[{"type":"text","value":"function"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-db8983"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-3155d7"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72a69d"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-75c3c8"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-72a69d"},"children":[{"type":"text","value":"|"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-75c3c8"},"children":[{"type":"text","value":"Bird"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":")"}]},{"type":"element","tag":"span","props":{"class":"ct-72a69d"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3155d7"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-72a69d"},"children":[{"type":"text","value":"is"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-75c3c8"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-607bf5"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"return"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-baefb8"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"as"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-1ce6ca"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":")."}]},{"type":"element","tag":"span","props":{"class":"ct-baefb8"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"!=="}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-17f6ad"},"children":[{"type":"text","value":"undefined"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":";"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"}"}]}]}]}]}]},{"type":"element","tag":"p","props":{},"children":[{"type":"text","value":"Usage:"}]},{"type":"element","tag":"code","props":{"code":"const pet = getSmallPet();\n \nif (isFish(pet)) {\n pet.swim();\n} else {\n pet.fly();\n}\n","language":"typescript"},"children":[{"type":"element","tag":"pre","props":{},"children":[{"type":"element","tag":"code","props":{"__ignoreMap":""},"children":[{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-a7e237"},"children":[{"type":"text","value":"const"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-77cb9b"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"="}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-819d0c"},"children":[{"type":"text","value":"getSmallPet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"if"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-819d0c"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-baefb8"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":")) {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-baefb8"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-819d0c"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"} "}]},{"type":"element","tag":"span","props":{"class":"ct-d944cb"},"children":[{"type":"text","value":"else"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-baefb8"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-819d0c"},"children":[{"type":"text","value":"fly"}]},{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-06adcc"},"children":[{"type":"text","value":"}"}]}]}]}]}]},{"type":"element","tag":"style","children":[{"type":"text","value":".ct-819d0c{color:#D2A8FF}.ct-77cb9b{color:#79C0FF}.ct-a7e237{color:#FF7B72}.ct-17f6ad{color:#79C0FF}.ct-1ce6ca{color:#FFA657}.ct-baefb8{color:#C9D1D9}.ct-d944cb{color:#FF7B72}.ct-06adcc{color:#C9D1D9}.ct-75c3c8{color:#FFA657}.ct-72a69d{color:#FF7B72}.ct-3155d7{color:#FFA657}.ct-db8983{color:#D2A8FF}.ct-607bf5{color:#C9D1D9}.ct-f71f08{color:#FF7B72}.light .ct-f71f08{color:#073642}.light .ct-607bf5{color:#657B83}.light .ct-db8983{color:#268BD2}.light .ct-3155d7{color:#657B83}.light .ct-72a69d{color:#859900}.light .ct-75c3c8{color:#268BD2}.light .ct-06adcc{color:#657B83}.light .ct-d944cb{color:#859900}.light .ct-baefb8{color:#268BD2}.light .ct-1ce6ca{color:#268BD2}.light .ct-17f6ad{color:#B58900}.light .ct-a7e237{color:#073642}.light .ct-77cb9b{color:#268BD2}.light .ct-819d0c{color:#268BD2}"}]}],"toc":{"title":"","searchDepth":2,"depth":2,"links":[]}},"_type":"markdown","_id":"content:Typescript:Type guards.md","_source":"content","_file":"Typescript/Type guards.md","_extension":"md"}