reading-notes

Error Handling and Debugging

• order of execution order in which statements are processed
• execution contexts one global execution context and each function creates a new execution context
• the stack JS terp processes on line at a time, stacks new function on top of current task
• execution context & hoisting when script enters new execution context
  • prepare
    • new scope created
    • variables, functions, arguments created
  • execute
  • assign values to variables
  • reference functions and run code
  • execute statements
• lexical scope linked to object they were defined within
• exception JS statement error causes, terp stops and looks for exception-handling code
• error object shows information about error
• dealing with errors
  • debug script
  • handle errors gracefully(error handling code)
• broswer dev tools JS console
  • console object
  • log data to console
    • console.log
    • console.info
    • console.warn
    • console.error
    • console.group
    • console.tab
    • console.assert
  • breakpoints pause execution of script on any line
    • stepping over breakpoint passes over functions, can step into functions
    • conditional breakpoints specify condition to trigger
    • debugger keyword creates breakpoint
• handling exceptions
  • try specify the code that you think might throw an exception in the try block
  • catch if try code blocks throws exception catch steps with an alternative code set
  • finally will run whether try block succeeds or fails
• throwing errors create your own error before interpreter creates them

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