Tutorial by Examples: allo

TCO is only available in strict mode As always check browser and Javascript implementations for support of any language features, and as with any javascript feature or syntax, it may change in the future. It provides a way to optimise recursive and deeply nested function calls by eliminating the n...

pip doesn't current contain a flag to allow a user to update all outdated packages in one shot. However, this can be accomplished by piping commands together in a Linux environment: pip list --outdated --local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip install -U This command takes all pa...

pip doesn't current contain a flag to allow a user to update all outdated packages in one shot. However, this can be accomplished by piping commands together in a Windows environment: for /F "delims= " %i in ('pip list --outdated --local') do pip install -U %i This command takes all pa...

This option allows you to clear a TLA for references and values at TLA allocation time and pre-fetch the next chunk. When an integer, a reference, or anything else is declared, it has a default value of 0 or null (depending upon type). At the appropriate time, you will need to clear these references...

When used with -XXallocClearChunkSize, this option sets the size of the chunks to be cleared. If this flag is used but no value is specified, the default is 512 bytes. Usage: -XXallocClearChunks -XXallocClearChunkSize=<size>[k|K][m|M][g|G]

CREATE UNIQUE INDEX idx_license_id ON Person(DrivingLicenseID) WHERE DrivingLicenseID IS NOT NULL GO This schema allows for a 0..1 relationship - people can have zero or one driving licenses and each license can only belong to one person

When you are copying a string into a malloced buffer, always remember to add 1 to strlen. char *dest = malloc(strlen(src)); /* WRONG */ char *dest = malloc(strlen(src) + 1); /* RIGHT */ strcpy(dest, src); This is because strlen does not include the trailing \0 in the length. If you take the ...

If realloc fails, it returns NULL. If you assign the value of the original buffer to realloc's return value, and if it returns NULL, then the original buffer (the old pointer) is lost, resulting in a memory leak. The solution is to copy into a temporary pointer, and if that temporary is not NULL, th...

PREPARE prepares a statement for execution EXECUTE executes a prepared statement DEALLOCATE PREPARE releases a prepared statement SET @s = 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse'; PREPARE stmt2 FROM @s; SET @a = 6; SET @b = 8; EXECUTE stmt2 USING @a, @b; Result: +------------+ |...

#include <stdio.h> #include <stdlib.h> int main (void) { int * pdata; size_t n; printf ("Enter the size of the array: "); fflush(stdout); /* Make sure the prompt gets printed to buffered stdout. */ if (1 != scanf("%zu", &n)) /* If zu is n...

If targeting Flash Player 11+, the built-in removeChildren method is the best way to remove all children: removeChildren(); //a start and end index can be passed For legacy applications, the same can be accomplished with a loop: while (numChildren > 0) { removeChildAt(0); }

The term 'heap' is a general computing term meaning an area of memory from which portions can be allocated and deallocated independently of the memory provided by the stack. In C++ the Standard refers to this area as the Free Store which is considered a more accurate term. Areas of memory allocate...

You can force deallocate objects even if their refcount isn't 0 in both Python 2 and 3. Both versions use the ctypes module to do so. WARNING: doing this will leave your Python environment unstable and prone to crashing without a traceback! Using this method could also introduce security problems ...

Default behavior when cloning an object is to perform a shallow copy of the object's fields. In that case, both the original object and the cloned object, hold references to the same objects. This example shows that behavior. import java.util.List; public class Sheep implements Cloneable { ...

It's easier to implement some UDFs on the worksheet if full column references can be passed in as parameters. However, due to the explicit nature of coding, any loop involving these ranges may be processing hundreds of thousands of cells that are completely empty. This reduces your VBA project (and ...

In many languages, new instances of a class are created using a special new keyword. In Ruby, new is also used to create instances of a class, but it isn't a keyword; instead, it's a static/class method, no different from any other static/class method. The definition is roughly this: class MyClass ...

To improve memory allocation performance, many TensorFlow users often use tcmalloc instead of the default malloc() implementation, as tcmalloc suffers less from fragmentation when allocating and deallocating large objects (such as many tensors). Some memory-intensive TensorFlow programs have been kn...

When you have a zoomed Image (or other content) you may want to drag around the Image to show all of its content in the zoomed in state. This can be achieved by implementing the PanGestureRecognizer. From code this looks like so: var panGesture = new PanGestureRecognizer(); panGesture.PanUpdated...

In Swift, memory management is done for you automatically using Automatic Reference Counting. (See Memory Management) Allocation is the process of reserving a spot in memory for an object, and in Swift understanding the performance of such requires some understanding of the heap and the stack. The h...

Example: Invoke different constructors by passing relevant parameters import java.lang.reflect.*; class NewInstanceWithReflection{ public NewInstanceWithReflection(){ System.out.println("Default constructor"); } public NewInstanceWithReflection( String a){ ...