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Mongodb update array $pull modifier

1. $pull modifier deletes qualifying elements from the array in the following format: { $pull: { <field1>: <value|condition>, <field2>: <value|condition>, ... } } 2. Specify a value to delete all lists Give a document under a stores collection { _id: 1, fruits: [ "apples", "pears", "oranges", "grapes", "bananas" ], vegetables: [ "carrots", "celery", "squash", "carrots" ] } { _id: 2, fruits:...

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commons-lang3 tool class learning (2)

From http://commons.apache.org/proper/commons-lang/javadocs/api-release/org/apache/commons/lang3/ Official documents to organize and remember for yourself 3. BooleanUtils Boolean Tool Class and(boolean...array) logic and BooleanUtils.and(true, true) = true BooleanUtils.and(false, false) = false BooleanUtils.and(true, false) = false BooleanUtils.and(true, true, false) = false BooleanUtils.and(true, true,...

programmer group

commons-lang3 tool class learning (2)

From http://commons.apache.org/proper/commons-lang/javadocs/api-release/org/apache/commons/lang3/ Official documents to organize and remember for yourself 3. BooleanUtils Boolean Tool Class and(boolean...array) logic and BooleanUtils.and(true, true) = true BooleanUtils.and(false, false) = false BooleanUtils.and(true, false) = false BooleanUtils.and(true, true, false) = false BooleanUtils.and(true, true,...

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The Apache Software Foundation Announces Apache® Wicket™ v9

Popular Open Source component-oriented server-side Java Web framework used to create robust Websites with faster and more maintainable code.Wakefield, MA —15 July 2020— The Apache Software Foundation (ASF), the all-volunteer developers, stewards, and incubators of more than 350 Open Source projects and initiatives, today announced Apache® WicketTM v9.0.0, the latest version of the Open Source Java framework for creating rich...

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Merge sort algorithm implemented in Java

The following is a merge sort algorithm implemented in Java, referencing Algorithms Unlocked by Thomas H. Cormen I read some blogs from other CSDN bloggers, and I think some details can be optimized, such as avoiding overflow due to too long array length, and using mid = low + (high - low) / 2 for mid For example, instead of creating a (high - low + 1) long array, you can create only the first half of the array[low...mid] These...

programmer group

Merge sort algorithm implemented in Java

The following is a merge sort algorithm implemented in Java, referencing Algorithms Unlocked by Thomas H. Cormen I read some blogs from other CSDN bloggers, and I think some details can be optimized, such as avoiding overflow due to too long array length, and using mid = low + (high - low) / 2 for mid For example, instead of creating a (high - low + 1) long array, you can create only the first half of the array[low...mid] These...