Question

想要检查对象数组中所有行的值是否相同，或者对象数组中所有列的值是否相同。我如何使用lodash有效地做到这一点？

String keyStorePassword = "123456";   
String configPath = "C:\\ssl\\";  
String keyStorePath = configPath + "client.ks";  
KeyStore ks = KeyStore.getInstance("jks");  
String trustStore = configPath + "trust.ts";  
java.lang.System.setProperty("javax.net.ssl.trustStore", trustStore);
java.lang.System.setProperty("javax.net.ssl.trustStorePassword", keyStorePassword);

            InputStream ksIs = new FileInputStream(keyStorePath);
            try {
                ks.load(ksIs, keyStorePassword.toCharArray());
            } finally {
                if (ksIs != null) {
                    ksIs.close();
                }
            }
            KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
            kmf.init(ks, keyStorePassword.toCharArray());

            TrustManager[] trustAllCerts = new TrustManager[] {
                    new X509TrustManager() {
                        public void checkClientTrusted(java.security.cert.X509Certificate[] certs, String authType) {
                        }

                        public void checkServerTrusted(java.security.cert.X509Certificate[] certs, String authType) {
                        }

                        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                            return null;
                        }
                    }
            };

            final SSLContext sslContext = SSLContext.getInstance("TLSv1.2");
            ConnectionFactory factory = new ActiveMQSslConnectionFactory(URL);
            sslContext.init(kmf.getKeyManagers(), trustAllCerts, new SecureRandom());       
            SslContext context = new SslContext();
            context.setSSLContext(sslContext);
            SslContext.setCurrentSslContext(context);
            Connection connection = factory.createConnection(loginName, pwd);
            connection.start();         
            Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            MessageProducer nonPersistentProducer = session.createProducer(null);
            session.close();
            connection.close();

在上面的例子中，对象数组中的所有行都是相同的。

Answer 1

如果我理解正确的约束，那怎么样？

var data = [
  {row: 0, col: 4},
  {row: 0, col: 1},
  {row: 0, col: 2},
];

function allTheSame(data, key) {
    return data.length && _.every(data, function (item) {
        return item[key] === data[0][key];
    });
}

console.log(_.any(['row', 'col'], function (key) {
    return allTheSame(data, key);
}));

请注意_.every和_.any都提前纾困，所以这应该尽可能高效。

另请注意，如果数组中没有元素，allTheSame将返回false。如果您希望将空列表视为“完全相同”，则可以切换到return data.length === 0 || _.every(...。

Answer 2

棘手的部分是在与lodash的同一次迭代中尝试检查列值或行值是否相同。但是，除非您正在处理无法形容的数据，否则这不应该是必要的。假设情况并非如此，这是简单的线性方法：

function isRowOrColSame(data) {

  var row = _.every(data, {'row': data[0].row})
  var col = _.every(data, {'col': data[0].col})
  
  return (row || col)
}

var data = [
  {row: 0, col: 4},
  {row: 0, col: 1},
  {row: 0, col: 2}
]

console.log(isRowOrColSame(data))

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.13.1/lodash.min.js"></script>

如果您需要解释每个功能发生了什么，请告诉我。我希望有所帮助！

检查对象数组中key的值是否相同 - Lodash

2 个答案: