A JavaScript execution context is a critical concept that defines the environment in which JavaScript code is executed. The execution context consists of two main components:
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Code Execution:
- This part involves the actual execution of the code line by line, interpreting and processing statements, and performing the actions specified in the script.
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Lexical Environment:
- The lexical environment includes the variables and their values that are accessible during the execution of the code. It encompasses the scope chain, which determines the visibility and accessibility of variables in the code. The lexical environment also includes a reference to the outer environment, allowing access to variables from the surrounding scopes.
These two components work together to facilitate the proper execution of JavaScript code while managing variable scopes and environments. Understanding the execution context is essential for comprehending how JavaScript handles variable scope, closures, and the flow of code execution.