{"id":66489,"date":"2025-05-03T12:11:37","date_gmt":"2025-05-03T04:11:37","guid":{"rendered":"https:\/\/fwq.ai\/blog\/66489\/"},"modified":"2025-05-03T12:11:37","modified_gmt":"2025-05-03T04:11:37","slug":"%e6%80%8e%e4%b9%88%e5%88%a4%e6%96%adjava%e4%b8%ad%e7%9a%84%e6%95%b0%e7%bb%84%e4%b8%ba%e7%a9%ba-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/66489\/","title":{"rendered":"\u600e\u4e48\u5224\u65adjava\u4e2d\u7684\u6570\u7ec4\u4e3a\u7a7a"},"content":{"rendered":"<blockquote><p>\n  \u662f\u7684\u3002java \u4e2d\u5224\u65ad\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\u6709\u4e24\u79cd\u65b9\u6cd5\uff1a1) \u4f7f\u7528 null \u68c0\u67e52) \u4f7f\u7528 length \u5c5e\u6027\uff08\u63a8\u8350\uff09\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202411\/16\/2024111604511690090.jpg\" class=\"aligncenter\" title=\"\u600e\u4e48\u5224\u65adjava\u4e2d\u7684\u6570\u7ec4\u4e3a\u7a7a\u63d2\u56fe\" alt=\"\u600e\u4e48\u5224\u65adjava\u4e2d\u7684\u6570\u7ec4\u4e3a\u7a7a\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u5224\u65ad Java \u4e2d\u7684\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a<\/strong><\/p>\n<p>\u5728 Java \u4e2d\uff0c\u5224\u65ad\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\u6709\u4e24\u79cd\u65b9\u6cd5\uff1a<\/p>\n<p><strong>\u65b9\u6cd5 1\uff1a\u4f7f\u7528 null \u68c0\u67e5<\/strong><\/p>\n<pre>int[] arr = null; \/\/ \u58f0\u660e\u4e00\u4e2a\u7a7a\u6570\u7ec4\nif (arr == null) {\n    \/\/ \u6570\u7ec4\u4e3a\u7a7a\n}<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>\u65b9\u6cd5 2\uff1a\u4f7f\u7528 length \u5c5e\u6027<\/strong><\/p>\n<p><span>\u7acb\u5373\u5b66\u4e60<\/span>\u201c\u201d\uff1b<\/p>\n<pre>int[] arr = new int[0]; \/\/ \u58f0\u660e\u4e00\u4e2a\u957f\u5ea6\u4e3a 0 \u7684\u6570\u7ec4\nif (arr.length == 0) {\n    \/\/ \u6570\u7ec4\u4e3a\u7a7a\n}<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u5176\u4e2d\uff0c<strong>\u63a8\u8350\u4f7f\u7528 length \u5c5e\u6027<\/strong>\u6765\u5224\u65ad\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\uff0c\u56e0\u4e3a\u8fd9\u79cd\u65b9\u6cd5\u66f4\u52a0\u5065\u58ee\uff0c\u4e0d\u4f1a\u51fa\u73b0 NullPointerException\u3002<\/p>\n<p><strong>\u7528\u6cd5\u793a\u4f8b\uff1a<\/strong><\/p>\n<pre>int[] arr = new int[10]; \/\/ \u58f0\u660e\u4e00\u4e2a\u957f\u5ea6\u4e3a 10 \u7684\u6570\u7ec4\n\n\/\/ \u68c0\u67e5\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\nif (arr.length == 0) {\n    System.out.println(\"\u6570\u7ec4\u4e3a\u7a7a\");\n} else {\n    System.out.println(\"\u6570\u7ec4\u4e0d\u4e3a\u7a7a\");\n}<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>\u6ce8\u610f\uff1a<\/strong><\/p>\n<ul>\n<li>\u5bf9\u4e8e\u591a\u7ef4\u6570\u7ec4\uff0c\u9700\u8981\u5206\u522b\u68c0\u67e5\u6bcf\u4e2a\u7ef4\u5ea6\u7684\u957f\u5ea6\u3002<\/li>\n<li>\u5bf9\u4e8e\u57fa\u672c\u7c7b\u578b\u6570\u7ec4\uff08\u5982 int[]\uff09\uff0c\u7a7a\u6570\u7ec4\u7684\u957f\u5ea6\u4e3a 0\u3002<\/li>\n<li>\u5bf9\u4e8e\u5f15\u7528\u7c7b\u578b\u6570\u7ec4\uff08\u5982 String[]\uff09\uff0c\u7a7a\u6570\u7ec4\u672c\u8eab\u4e3a null\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662f\u600e\u4e48\u5224\u65adjava\u4e2d\u7684\u6570\u7ec4\u4e3a\u7a7a\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8IDCBABY\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u662f\u7684\u3002java \u4e2d\u5224\u65ad\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\u6709\u4e24\u79cd\u65b9\u6cd5\uff1a1) \u4f7f\u7528 null \u68c0\u67e52) \u4f7f\u7528 length \u5c5e\u6027\uff08\u63a8\u8350\uff09 \u5982\u4f55\u5224\u65ad Java \u4e2d\u7684\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a \u5728 Java \u4e2d\uff0c\u5224\u65ad\u6570\u7ec4\u662f\u5426\u4e3a\u7a7a\u6709\u4e24\u79cd\u65b9\u6cd5\uff1a \u65b9\u6cd5 1\uff1a\u4f7f\u7528 null \u68c0\u67e5 int[] arr = null; \/\/ \u58f0\u660e\u4e00\u4e2a\u7a7a\u6570\u7ec4 if (arr == null) { \/\/ \u6570\u7ec4\u4e3a\u7a7a } \u767b\u5f55\u540e\u590d\u5236 \u65b9\u6cd5 2\uff1a\u4f7f\u7528 length \u5c5e\u6027 \u7acb\u5373\u5b66\u4e60\u201c\u201d\uff1b int[] arr = new int[0]; \/\/ \u58f0\u660e\u4e00\u4e2a\u957f\u5ea6\u4e3a 0 \u7684\u6570\u7ec4 if (arr.length == 0) { \/\/ \u6570\u7ec4\u4e3a\u7a7a } [&hellip;]<\/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-66489","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/66489","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=66489"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/66489\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=66489"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=66489"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=66489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}