muerwre.github.io/api/_content/query/iZIUw8pCoM.json
muerwre c4cc70ced6 commit 7d311fd60e8e534e3b641d1179480b27b472d1e2
Author: Fedor Katurov <gotham48@gmail.com>
Date:   Thu Nov 3 16:04:38 2022 +0600

    fixed headers size
2022-11-03 10:07:05 +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-3e88fe"},"children":[{"type":"text","value":"function"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-96a544"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-f31f3b"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-96df25"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-851fa7"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-96df25"},"children":[{"type":"text","value":"|"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-851fa7"},"children":[{"type":"text","value":"Bird"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":")"}]},{"type":"element","tag":"span","props":{"class":"ct-96df25"},"children":[{"type":"text","value":":"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-f31f3b"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-96df25"},"children":[{"type":"text","value":"is"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-851fa7"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-f1d349"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"return"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-50f970"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"as"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-0d7879"},"children":[{"type":"text","value":"Fish"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":")."}]},{"type":"element","tag":"span","props":{"class":"ct-50f970"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"!=="}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-38af6a"},"children":[{"type":"text","value":"undefined"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":";"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"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-01bcf2"},"children":[{"type":"text","value":"const"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-3fd1a6"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"="}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-c215b1"},"children":[{"type":"text","value":"getSmallPet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"if"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" ("}]},{"type":"element","tag":"span","props":{"class":"ct-c215b1"},"children":[{"type":"text","value":"isFish"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"("}]},{"type":"element","tag":"span","props":{"class":"ct-50f970"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":")) {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-50f970"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-c215b1"},"children":[{"type":"text","value":"swim"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"} "}]},{"type":"element","tag":"span","props":{"class":"ct-dfad5f"},"children":[{"type":"text","value":"else"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" {"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":" "}]},{"type":"element","tag":"span","props":{"class":"ct-50f970"},"children":[{"type":"text","value":"pet"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"."}]},{"type":"element","tag":"span","props":{"class":"ct-c215b1"},"children":[{"type":"text","value":"fly"}]},{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"();"}]}]},{"type":"element","tag":"span","props":{"class":"line"},"children":[{"type":"element","tag":"span","props":{"class":"ct-f91a65"},"children":[{"type":"text","value":"}"}]}]}]}]}]},{"type":"element","tag":"style","children":[{"type":"text","value":".ct-c215b1{color:#D2A8FF}.ct-3fd1a6{color:#79C0FF}.ct-01bcf2{color:#FF7B72}.ct-38af6a{color:#79C0FF}.ct-0d7879{color:#FFA657}.ct-50f970{color:#C9D1D9}.ct-dfad5f{color:#FF7B72}.ct-f91a65{color:#C9D1D9}.ct-851fa7{color:#FFA657}.ct-96df25{color:#FF7B72}.ct-f31f3b{color:#FFA657}.ct-96a544{color:#D2A8FF}.ct-f1d349{color:#C9D1D9}.ct-3e88fe{color:#FF7B72}.light .ct-3e88fe{color:#073642}.light .ct-f1d349{color:#657B83}.light .ct-96a544{color:#268BD2}.light .ct-f31f3b{color:#657B83}.light .ct-96df25{color:#859900}.light .ct-851fa7{color:#268BD2}.light .ct-f91a65{color:#657B83}.light .ct-dfad5f{color:#859900}.light .ct-50f970{color:#268BD2}.light .ct-0d7879{color:#268BD2}.light .ct-38af6a{color:#B58900}.light .ct-01bcf2{color:#073642}.light .ct-3fd1a6{color:#268BD2}.light .ct-c215b1{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"}