Różnica między var, pozwól, const
// var is a function scope ***
if(true){
var varVariable = 'This is var';
var varVariable = 'This is var again';
}
console.log(varVariable); // This is var again
// let is a block scope ***
if(true){
let letVariable = 'This is let';
let letVariable = 'This is let again';
// let variable can't re-define but we can re-assign value
console.log(letVariable); // let letVariable = 'This is let again';^SyntaxError: Identifier 'letVariable' has already been declared
}
console.log(letVariable); //ReferenceError: letVariable is not defined
// const variable can't re-define and re-assign value
// const is a block scope ***
if(true){
const constVarible = {
name: 'JavaScript',
age: '25 years',
};
constVarible.name = 'JS';
console.log(constVarible) // {name: 'JS',age: '25 years'} <= we can update const variable declared object
}
Md. Asif Iqbal
