Here is the first post about ES6 features in lifestyle. This story is about let & const😎. This two guys did the old man - Var.🕵
Let's figure out, how they work in examples.
It's let, don't mess with him out from the block 😎, don't try to talk about him behind his back. If you want to make some variables only for your block, or even for each iteration of loop, let can help you.
{ /* Don't even try to talk about me behind my back, it works with var,
not with me.💪 If you try, you've got reference error, boom!💥*/
console.log(varFromTheBlock);
// ReferenceError
let varFromTheBlock = "I'm Var from the Block, don't mess with me out from the block";
// Cause you got reference error, dude, you don't want it.
console.log(varFromTheBlock);
// "I'm Var from the Block, don't mess with me out from the block"
}
console.log(varFromTheBlock); //ReferenceError: varFromTheBlock is not defined
// let in for loop
var arrForIteration = [];
for (let i = 0; i < 5; i++){
arrForIteration.push( function(){
console.log( i );
} );
}
arrForIteration[3]();//3
It's const💪, he looks like let, but he is more principled and conservative. He is like a rock. If you want to create something, that never can be changed by somebody else, he can help you.
{
const bigConst = ['cars','weapons'];
// Hey I'm bigConst and I work for some huge array.🕵
bigConst.push('cash');
// Yes I can talk with array if you want and bring him some 'cash' 💵
console.log( bigConst ); // ['cars','weapons','cash']
// But don't try to broke my powerful connections with guys, which I'm working for!
bigConst = 'plant'; //TypeError
// I told you! It's typeError, man.
}
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