2-10 Creation and hoisting

  • hoisting : before js code is run line by line, js engine set memory space for the variables
  • all variables is initialized to undefined in js

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b();
console.log(a);

var a = 'Bello';
function b (){
  console.log('called b');
}
/*
called b
undefined
 */
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b();
console.log(a);

function b (){
  console.log('called b');
}

/*
called b
Error!!
*/