muerwre.github.io/api/_content/query/iZIUw8pCoM.json
muerwre cf4fa8656b commit 387fa7ce1b
Author: Fedor Katurov <gotham48@gmail.com>
Date:   Fri Nov 11 17:27:44 2022 +0600

    fixed colors on writing.svg
2022-11-11 11:29:35 +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-055aee"},"children":[{"type":"text","value":"function"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-39457b"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-d24c44"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-4f9c71"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d081f8"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-4f9c71"},"children":[{"type":"text","value":"|"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d081f8"},"children":[{"type":"text","value":"Bird"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":")"}]},{"type":"element","tag":"span","props":{"class":"ct-4f9c71"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d24c44"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-4f9c71"},"children":[{"type":"text","value":"is"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d081f8"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-ad278c"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"return"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-e17345"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"as"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-08870b"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":")."}]},{"type":"element","tag":"span","props":{"class":"ct-e17345"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"!=="}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-1448c1"},"children":[{"type":"text","value":"undefined"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":";"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"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-0975fa"},"children":[{"type":"text","value":"const"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-6f97dc"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"="}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-231390"},"children":[{"type":"text","value":"getSmallPet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"if"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-231390"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-e17345"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":")) {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-e17345"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-231390"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"} "}]},{"type":"element","tag":"span","props":{"class":"ct-2457f1"},"children":[{"type":"text","value":"else"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-e17345"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-231390"},"children":[{"type":"text","value":"fly"}]},{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-72ca1b"},"children":[{"type":"text","value":"}"}]}]}]}]}]},{"type":"element","tag":"style","children":[{"type":"text","value":".ct-231390{color:#D2A8FF}.ct-6f97dc{color:#79C0FF}.ct-0975fa{color:#FF7B72}.ct-1448c1{color:#79C0FF}.ct-08870b{color:#FFA657}.ct-e17345{color:#C9D1D9}.ct-2457f1{color:#FF7B72}.ct-72ca1b{color:#C9D1D9}.ct-d081f8{color:#FFA657}.ct-4f9c71{color:#FF7B72}.ct-d24c44{color:#FFA657}.ct-39457b{color:#D2A8FF}.ct-ad278c{color:#C9D1D9}.ct-055aee{color:#FF7B72}.light .ct-055aee{color:#073642}.light .ct-ad278c{color:#657B83}.light .ct-39457b{color:#268BD2}.light .ct-d24c44{color:#657B83}.light .ct-4f9c71{color:#859900}.light .ct-d081f8{color:#268BD2}.light .ct-72ca1b{color:#657B83}.light .ct-2457f1{color:#859900}.light .ct-e17345{color:#268BD2}.light .ct-08870b{color:#268BD2}.light .ct-1448c1{color:#B58900}.light .ct-0975fa{color:#073642}.light .ct-6f97dc{color:#268BD2}.light .ct-231390{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"}