precompiled

function fn(a,c){
            console.log(a) //f a(){}
            var a = 123
            console.log(a) / / 123
            console.log(c) //f c(){}
            function a(){}
            if(false) {var d=678
            }
            console.log(d)//undefined
            console.log(b)//undefined
            var b =function() {}
            console.log(b)//f(){}
            function c(){}
            console.log(c)//f c(){}
        }
        fn(1.2)
        / / the precompiled
        // Scope creation phase precompile phase
        // What was done during precompilation
        The AO object is accessed by the JS engine itself
        // the function declaration overwrites the variable declaration. // The function declaration overwrites the variable declarationAO: {a:undefined 1 function a(){}
        c:undefined 2 function c(){}
        d:undefined
        b:undefined
        }

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