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Convert a Map to a POJO
...Value is the right answer, but don't create an ObjectMapper instance every time. It's expensive to create and thread-safe, so create one and cache it somewhere.
– glade
Feb 26 '17 at 23:06
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Why would an Enum implement an Interface?
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First time ever seeing that Enum syntax (with the curly braces after the members), and I've been programming with Java for 6 years. TIL.
– jrahhali
Aug 29 '19 at 23:44
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What is a columnar database?
... (blocks ) needs to be brought to main memory, which includes lots of seek time from disk to bring all block from disk to ram, even if you are interested only in column which helps you to provide sales report. Whereas in column oriented scheme columns are stored contiguously in the blocks, which mak...
Get cookie by name
.... pop), and repeat the same process, but now with ";" as a token, but this time pulling out the left string (i.e. shift) to get the actual token value.
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The tilde operator in Python
...ssert ~np.True_ == np.False_
Reversing logical value can be useful sometimes, e.g., below ~ operator is used to cleanse your dataset and return you a column without NaN.
from numpy import NaN
import pandas as pd
matrix = pd.DataFrame([1,2,3,4,NaN], columns=['Number'], dtype='float64')
# Remove...
How does the Java 'for each' loop work?
...ment primitive-int array (A is iterator, B is index):
[C:\java_code\]java TimeIteratorVsIndexIntArray 1000000
Test A: 358,597,622 nanoseconds
Test B: 269,167,681 nanoseconds
B faster by 89,429,941 nanoseconds (24.438799231635727% faster)
[C:\java_code\]java TimeIteratorVsIndexIntArray 1000000
Test...
Parse date without timezone javascript
I want to parse date without timezone in JavaScript. I have tried:
12 Answers
12
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How do you do a deep copy of an object in .NET? [duplicate]
...work.
Your source file must include the following code:
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
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When do you use varargs in Java?
...ou consider adding a precondition check if (args.length == 0) throw new RuntimeException("foo"); instead? (Since the caller was violating the contract)
– Micha Wiedenmann
Apr 29 '13 at 14:46
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String is immutable. What exactly is the meaning? [duplicate]
...so "bar" is a reference to the same String instance regardless of how many times it appears in your code.
The "hello" creates one instance that is pooled, and the new String(...) creates a non-pooled instance. Try System.out.println(("hello" == "hello") + "," + (new String("hello") == "hello") + ...