Understanding JavaScript's Delete Operator: A Root to Understanding Object Deletion
In JavaScript, the delete operator sparks confusion among programmers. Consider the code snippet below:
var obj = {
helloText: "Hello World!"
};
var foo = obj;
delete obj;
Unexpectedly, after executing this code, obj becomes null while foo still accesses the same object. This behavior contradicts the presumed ability of the delete operator to erase objects from memory.
Understanding this peculiarity lies in the nature of the delete operator itself. It merely removes references to objects, not the objects themselves. If deleting references also stripped objects from memory, any remaining references would become corrupted and cause crashing errors (like those encountered in C "delete" operations). Additionally, removing all references would require excessive bookkeeping or overhead memory for each object.
JavaScript employs a garbage collector, which eradicates objects that are no longer accessible. As such, explicitly deleting objects isn't imperative; the collector will handle their removal.
However, removing references to objects manually provides the garbage collector with greater insight into what can be reclaimed. Retaining numerous references to a large object can hinder its deletion, even if it's no longer needed elsewhere in the program.
The above is the detailed content of Does JavaScript's `delete` Operator Actually Delete Objects?. For more information, please follow other related articles on the PHP Chinese website!
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