{"id":4704,"date":"2023-01-04T17:44:53","date_gmt":"2023-01-04T09:44:53","guid":{"rendered":"https:\/\/badgameshow.com\/steven\/?p=4704"},"modified":"2023-01-04T17:44:53","modified_gmt":"2023-01-04T09:44:53","slug":"%e8%a7%a3%e6%b1%bareact-js%e4%b8%adtypeerrorcannotconvertundefinedornulltoobject%e7%9a%84%e9%8c%af%e8%aa%a4","status":"publish","type":"post","link":"https:\/\/badgameshow.com\/steven\/react-js\/%e8%a7%a3%e6%b1%bareact-js%e4%b8%adtypeerrorcannotconvertundefinedornulltoobject%e7%9a%84%e9%8c%af%e8%aa%a4\/","title":{"rendered":"\u89e3\u6c7aReact.js\u4e2d&#8221;TypeError:Cannotconvertundefinedornulltoobject&#8221;\u7684\u932f\u8aa4"},"content":{"rendered":"<p><meta name=\"keywords\" content=\"React.js, TypeError, Cannot convert undefined or null to object\"><\/p>\n<h1>\u89e3\u6c7a React.js &#8220;TypeError: Cannot convert undefined or null to object&#8221; \u932f\u8aa4<\/h1>\n<p>React.js \u662f\u4e00\u500b\u7528\u65bc\u69cb\u5efa\u7528\u6236\u7aef\u61c9\u7528\u7a0b\u5e8f\u7684 JavaScript \u6846\u67b6\uff0c\u5b83\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5feb\u901f\u69cb\u5efa\u529f\u80fd\u5f37\u5927\u7684\u61c9\u7528\u7a0b\u5e8f\u3002\u7136\u800c\uff0c\u5728\u958b\u767c\u904e\u7a0b\u4e2d\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u9047\u5230\u4e00\u4e9b\u554f\u984c\uff0c\u5176\u4e2d\u4e00\u500b\u662f &#8220;TypeError: Cannot convert undefined or null to object&#8221; \u932f\u8aa4\u3002<\/p>\n<p>\u9019\u500b\u932f\u8aa4\u901a\u5e38\u662f\u7531\u65bc\u958b\u767c\u8005\u5728\u4f7f\u7528 React.js \u6642\u6c92\u6709\u6b63\u78ba\u5730\u5b9a\u7fa9\u7269\u4ef6\u800c\u5c0e\u81f4\u7684\u3002\u4f8b\u5982\uff0c\u5982\u679c\u958b\u767c\u8005\u5617\u8a66\u4f7f\u7528\u4e00\u500b\u672a\u5b9a\u7fa9\u7684\u7269\u4ef6\uff0c\u5247\u53ef\u80fd\u6703\u51fa\u73fe\u6b64\u932f\u8aa4\u3002<\/p>\n<p>\u8981\u89e3\u6c7a\u6b64\u932f\u8aa4\uff0c\u958b\u767c\u8005\u9700\u8981\u78ba\u4fdd\u4ed6\u5011\u6b63\u78ba\u5730\u5b9a\u7fa9\u4e86\u6240\u6709\u7269\u4ef6\uff0c\u4e26\u78ba\u4fdd\u4ed6\u5011\u6b63\u78ba\u5730\u4f7f\u7528\u4e86\u5b83\u5011\u3002\u4f8b\u5982\uff0c\u5982\u679c\u958b\u767c\u8005\u5617\u8a66\u4f7f\u7528\u4e00\u500b\u672a\u5b9a\u7fa9\u7684\u7269\u4ef6\uff0c\u5247\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u7a0b\u5f0f\u78bc\u4f86\u5b9a\u7fa9\u8a72\u7269\u4ef6\uff1a<\/p>\n<pre class=\"brush: javascript\">\nlet myObject = {\n  name: 'John',\n  age: 25\n};\n<\/pre>\n<p>\u6b64\u5916\uff0c\u958b\u767c\u8005\u9084\u53ef\u4ee5\u4f7f\u7528 <code>typeof<\/code> \u904b\u7b97\u5b50\u4f86\u6aa2\u67e5\u7269\u4ef6\u662f\u5426\u5df2\u5b9a\u7fa9\uff1a<\/p>\n<pre class=\"brush: javascript\">\nif (typeof myObject !== 'undefined') {\n  \/\/ Do something with myObject\n}\n<\/pre>\n<p>\u53e6\u5916\uff0c\u958b\u767c\u8005\u9084\u53ef\u4ee5\u4f7f\u7528 <code>console.log()<\/code> \u4f86\u6aa2\u67e5\u7269\u4ef6\u662f\u5426\u6b63\u78ba\u5b9a\u7fa9\uff1a<\/p>\n<pre class=\"brush: javascript\">\nconsole.log(myObject);\n<\/pre>\n<p>\u5982\u679c\u958b\u767c\u8005\u6b63\u78ba\u5730\u5b9a\u7fa9\u4e86\u7269\u4ef6\uff0c\u5247\u53ef\u4ee5\u770b\u5230\u7269\u4ef6\u7684\u5167\u5bb9\u3002<\/p>\n<p>\u6b64\u5916\uff0c\u958b\u767c\u8005\u9084\u53ef\u4ee5\u4f7f\u7528 <code>JSON.stringify()<\/code> \u4f86\u6aa2\u67e5\u7269\u4ef6\u662f\u5426\u6b63\u78ba\u5b9a\u7fa9\uff1a<\/p>\n<pre class=\"brush: javascript\">\nconsole.log(JSON.stringify(myObject));\n<\/pre>\n<p>\u5982\u679c\u958b\u767c\u8005\u6b63\u78ba\u5730\u5b9a\u7fa9\u4e86\u7269\u4ef6\uff0c\u5247\u53ef\u4ee5\u770b\u5230\u7269\u4ef6\u7684\u5167\u5bb9\u3002<\/p>\n<p>\u7e3d\u800c\u8a00\u4e4b\uff0c\u8981\u89e3\u6c7a React.js &#8220;TypeError: Cannot convert undefined or null to object&#8221; 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