{"id":53622,"date":"2024-12-03T11:45:18","date_gmt":"2024-12-03T03:45:18","guid":{"rendered":"https:\/\/fwq.ai\/blog\/53622\/"},"modified":"2024-12-03T11:45:18","modified_gmt":"2024-12-03T03:45:18","slug":"javascript-%e4%b8%ad-var-%e5%92%8c-let-%e5%85%b3%e9%94%ae%e5%ad%97%e5%a3%b0%e6%98%8e%e5%8f%98%e9%87%8f%e7%9a%84%e5%8c%ba%e5%88%ab%e6%98%af%e4%bb%80%e4%b9%88%ef%bc%9f-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/53622\/","title":{"rendered":"JavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f"},"content":{"rendered":"<p><b><\/b>     <\/p>\n<h1>JavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f<\/h1>\n<p>\u600e\u4e48\u5165\u95e8\u6587\u7ae0\u7f16\u7a0b\uff1f\u9700\u8981\u5b66\u4e60\u54ea\u4e9b\u77e5\u8bc6\u70b9\uff1f\u8fd9\u662f\u65b0\u624b\u4eec\u521a\u63a5\u89e6\u7f16\u7a0b\u65f6\u5e38\u89c1\u7684\u95ee\u9898\uff1b\u4e0b\u9762\u7c73\u4e91\u5c31\u6765\u7ed9\u5927\u5bb6\u6574\u7406\u5206\u4eab\u4e00\u4e9b\u77e5\u8bc6\u70b9\uff0c\u5e0c\u671b\u80fd\u591f\u7ed9\u521d\u5b66\u8005\u4e00\u4e9b\u5e2e\u52a9\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u4ecb\u7ecd\u300aJavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u300b\uff0c\u6d89\u53ca\u5230\uff0c\u6709\u9700\u8981\u7684\u53ef\u4ee5\u6536\u85cf\u4e00\u4e0b<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241202\/1733143164674daa7c742e9.jpg\" class=\"aligncenter\" title=\"JavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u63d2\u56fe\" alt=\"JavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>js\u4e2dvar\u548clet\u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u5dee\u5f02<\/strong><\/p>\n<p>\u5728JavaScript\u4e2d\uff0c\u58f0\u660e\u53d8\u91cf\u53ef\u4ee5\u4f7f\u7528var\u548clet\u5173\u952e\u5b57\u3002\u4e0b\u9762\u4ecb\u7ecd\u5176\u533a\u522b\uff1a<\/p>\n<p><strong>\u8303\u56f4<\/strong><\/p>\n<ul>\n<li>var\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u53ef\u4ee5\u5728\u6574\u4e2a\u811a\u672c\u4e2d\u8bbf\u95ee\u3002<\/li>\n<li>let\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5757\u7ea7\u4f5c\u7528\u57df\uff0c\u4ec5\u5728\u58f0\u660e\u5757\u5185\u53ef\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n<p><strong>\u91cd\u65b0\u58f0\u660e<\/strong><\/p>\n<ul>\n<li>var\u58f0\u660e\u7684\u53d8\u91cf\u53ef\u4ee5\u5728\u540c\u4e00\u4e0b\u4e00\u4e2a\u4f5c\u7528\u57df\u4e2d\u91cd\u65b0\u58f0\u660e\u3002<\/li>\n<li>let\u58f0\u660e\u7684\u53d8\u91cf\u5982\u679c\u5728\u540c\u4e00\u4e2a\u5757\u7ea7\u4f5c\u7528\u57df\u5185\u88ab\u91cd\u65b0\u58f0\u660e\uff0c\u4f1a\u62a5\u9519\u3002<\/li>\n<\/ul>\n<p><strong>\u518d\u8d4b\u503c<\/strong><\/p>\n<ul>\n<li>var\u548clet\u58f0\u660e\u7684\u53d8\u91cf\u90fd\u53ef\u4ee5\u91cd\u65b0\u8d4b\u503c\u3002<\/li>\n<\/ul>\n<p><strong>const<\/strong><\/p>\n<p>\u9664\u4e86var\u548clet\uff0c\u8fd8\u6709const\u5173\u952e\u5b57\u53ef\u4ee5\u58f0\u660e\u5c40\u90e8\u53d8\u91cf\u3002\u4e0elet\u7c7b\u4f3c\uff0cconst\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5757\u7ea7\u4f5c\u7528\u57df\uff0c\u4f46\u662f\u65e0\u6cd5\u91cd\u65b0\u8d4b\u503c\u3002<\/p>\n<p>\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300aJavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u7c73\u4e91\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591a\u6587\u7ae0\u77e5\u8bc6\uff01<\/p>\n<dl>\n<dt><\/dt>\n<dd>\n   \u6587\u7ae0\u9644\u4ef6\u8868\u8bbe\u8ba1\uff1a\u5916\u952e\u5173\u8054\u8fd8\u662f\u5b58\u50a8\u9644\u4ef6ID\uff1f\n <\/dd>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>JavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f \u600e\u4e48\u5165\u95e8\u6587\u7ae0\u7f16\u7a0b\uff1f\u9700\u8981\u5b66\u4e60\u54ea\u4e9b\u77e5\u8bc6\u70b9\uff1f\u8fd9\u662f\u65b0\u624b\u4eec\u521a\u63a5\u89e6\u7f16\u7a0b\u65f6\u5e38\u89c1\u7684\u95ee\u9898\uff1b\u4e0b\u9762\u7c73\u4e91\u5c31\u6765\u7ed9\u5927\u5bb6\u6574\u7406\u5206\u4eab\u4e00\u4e9b\u77e5\u8bc6\u70b9\uff0c\u5e0c\u671b\u80fd\u591f\u7ed9\u521d\u5b66\u8005\u4e00\u4e9b\u5e2e\u52a9\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u4ecb\u7ecd\u300aJavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u300b\uff0c\u6d89\u53ca\u5230\uff0c\u6709\u9700\u8981\u7684\u53ef\u4ee5\u6536\u85cf\u4e00\u4e0b js\u4e2dvar\u548clet\u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u5dee\u5f02 \u5728JavaScript\u4e2d\uff0c\u58f0\u660e\u53d8\u91cf\u53ef\u4ee5\u4f7f\u7528var\u548clet\u5173\u952e\u5b57\u3002\u4e0b\u9762\u4ecb\u7ecd\u5176\u533a\u522b\uff1a \u8303\u56f4 var\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5168\u5c40\u4f5c\u7528\u57df\uff0c\u53ef\u4ee5\u5728\u6574\u4e2a\u811a\u672c\u4e2d\u8bbf\u95ee\u3002 let\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5757\u7ea7\u4f5c\u7528\u57df\uff0c\u4ec5\u5728\u58f0\u660e\u5757\u5185\u53ef\u8bbf\u95ee\u3002 \u91cd\u65b0\u58f0\u660e var\u58f0\u660e\u7684\u53d8\u91cf\u53ef\u4ee5\u5728\u540c\u4e00\u4e0b\u4e00\u4e2a\u4f5c\u7528\u57df\u4e2d\u91cd\u65b0\u58f0\u660e\u3002 let\u58f0\u660e\u7684\u53d8\u91cf\u5982\u679c\u5728\u540c\u4e00\u4e2a\u5757\u7ea7\u4f5c\u7528\u57df\u5185\u88ab\u91cd\u65b0\u58f0\u660e\uff0c\u4f1a\u62a5\u9519\u3002 \u518d\u8d4b\u503c var\u548clet\u58f0\u660e\u7684\u53d8\u91cf\u90fd\u53ef\u4ee5\u91cd\u65b0\u8d4b\u503c\u3002 const \u9664\u4e86var\u548clet\uff0c\u8fd8\u6709const\u5173\u952e\u5b57\u53ef\u4ee5\u58f0\u660e\u5c40\u90e8\u53d8\u91cf\u3002\u4e0elet\u7c7b\u4f3c\uff0cconst\u58f0\u660e\u7684\u53d8\u91cf\u5177\u6709\u5757\u7ea7\u4f5c\u7528\u57df\uff0c\u4f46\u662f\u65e0\u6cd5\u91cd\u65b0\u8d4b\u503c\u3002 \u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300aJavaScript \u4e2d var \u548c let \u5173\u952e\u5b57\u58f0\u660e\u53d8\u91cf\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u7c73\u4e91\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591a\u6587\u7ae0\u77e5\u8bc6\uff01 \u6587\u7ae0\u9644\u4ef6\u8868\u8bbe\u8ba1\uff1a\u5916\u952e\u5173\u8054\u8fd8\u662f\u5b58\u50a8\u9644\u4ef6ID\uff1f<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-53622","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/53622","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=53622"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/53622\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=53622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=53622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=53622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}