muerwre.github.io/api/_content/query/iZIUw8pCoM.json
muerwre 468abb8bc0 commit e92e0685ed8d7a331fd961e21085ec5b445cf3aa
Author: Fedor Katurov <gotham48@gmail.com>
Date:   Thu Nov 3 18:52:26 2022 +0600

    added empty projects page
2022-11-03 12:54:16 +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-046d7b"},"children":[{"type":"text","value":"function"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-527549"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-d96e74"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-a37712"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-f189e5"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-a37712"},"children":[{"type":"text","value":"|"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-f189e5"},"children":[{"type":"text","value":"Bird"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":")"}]},{"type":"element","tag":"span","props":{"class":"ct-a37712"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-d96e74"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-a37712"},"children":[{"type":"text","value":"is"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-f189e5"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-b4c07a"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"return"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-5a0e09"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"as"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-606086"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":")."}]},{"type":"element","tag":"span","props":{"class":"ct-5a0e09"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"!=="}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-8c8025"},"children":[{"type":"text","value":"undefined"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":";"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"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-b7a6b6"},"children":[{"type":"text","value":"const"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-efc9d5"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"="}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-c7c789"},"children":[{"type":"text","value":"getSmallPet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"if"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-c7c789"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-5a0e09"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":")) {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-5a0e09"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-c7c789"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"} "}]},{"type":"element","tag":"span","props":{"class":"ct-3434a0"},"children":[{"type":"text","value":"else"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-5a0e09"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-c7c789"},"children":[{"type":"text","value":"fly"}]},{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-b9efb7"},"children":[{"type":"text","value":"}"}]}]}]}]}]},{"type":"element","tag":"style","children":[{"type":"text","value":".ct-c7c789{color:#D2A8FF}.ct-efc9d5{color:#79C0FF}.ct-b7a6b6{color:#FF7B72}.ct-8c8025{color:#79C0FF}.ct-606086{color:#FFA657}.ct-5a0e09{color:#C9D1D9}.ct-3434a0{color:#FF7B72}.ct-b9efb7{color:#C9D1D9}.ct-f189e5{color:#FFA657}.ct-a37712{color:#FF7B72}.ct-d96e74{color:#FFA657}.ct-527549{color:#D2A8FF}.ct-b4c07a{color:#C9D1D9}.ct-046d7b{color:#FF7B72}.light .ct-046d7b{color:#073642}.light .ct-b4c07a{color:#657B83}.light .ct-527549{color:#268BD2}.light .ct-d96e74{color:#657B83}.light .ct-a37712{color:#859900}.light .ct-f189e5{color:#268BD2}.light .ct-b9efb7{color:#657B83}.light .ct-3434a0{color:#859900}.light .ct-5a0e09{color:#268BD2}.light .ct-606086{color:#268BD2}.light .ct-8c8025{color:#B58900}.light .ct-b7a6b6{color:#073642}.light .ct-efc9d5{color:#268BD2}.light .ct-c7c789{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"}