Access declaration, but no initialized variable

let aaa
console.log(aaa) // undefined 
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Access properties that do not exist

let aaa = {}
console.log(aaa.c) // undefined
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3. No explicit values are passed to the parameters of the access function

(function (b){ 
    console.log(b) 
})() // undefined
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4. Access any variable set to undefined

let aaa = undefined
console.log(aaa); // undefined 
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5. Functions that do not define a return implicitly return

function aaa(){}
console.log(aaa()) // undefined 
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The function return does not explicitly return anything

function aaa(){ 
    return 
}
console.log(aaa()) // undefined
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