What is the hoisting?
It’s a characteristic that is assigned in the top level when it’s assigned with var in the interpreting progress.
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| console.log(foo); // undefined
var foo;
foo = 'It is foo.';
console.log(foo); // It is foo.
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This characteristic occurs wrong situation like below code.
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| console.log(foo); // undefined
var foo;
foo = 3;
console.log(foo); // 3
function bar() {
// Look at here!
console.log(foo); // undefined
var foo;
foo = 'It is foo.';
console.log(foo); // It is foo.
}
bar();
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The reason why it’s printed as undefined, it referenced foo of function region scope in the function.
So we noticed hoisting is working in each scope.
How about assign a function?
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| console.log(typeof foo); // function
foo(); // hoisting function test
function foo() {
console.log('hoisting function test');
}
console.log(typeof foo); // function
foo(); // hoisting function test
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Then how about when you assign the function to a value?
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| console.log(typeof foo); // undefined
var foo = function () {
console.log('hoisting function test');
}
console.log(typeof foo); // function
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Is the result you expected?
CozyFex