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javascriptwindow-object

calling a function from its string name on Window object

Why is the test fuction declaration not found in the window object? Thanks

!function(){
   function test(){
    console.log("testing");
   }   
   var check = window["test"]
   console.log(check); //undefined
 }();
Solution

  • Since function test() is local to the scope of the toplevel function expression, it's not bound to window, the global scope. You can refer to it as a local variable:

    !function() {
    function test() {
        console.log('testing')
    }
    console.log(test)
}()

    Or bind it directly to window for a global variable:

    !function() {
    window.test = function test() {
        console.log('testing')
    }
    var check = window['test']
    console.log(check)
}()

    You cannot access the local scope as a variable - see this question for more details.