https://code-garage.fr › blog › quelles-sont-les-differences-entre-var-let-et-const-en...

let sert à définir une variable locale. const sert à déclarer une référence constante. Attention, une référence constante ne veut pas dire que la valeur derrière la référence est "immutable", mais que la référence elle-même est immutable.

https://www.freecodecamp.org › news › var-let-and-const-whats-the-difference

var declarations are globally scoped or function scoped while let and const are block scoped. var variables can be updated and re-declared within its scope; let variables can be updated but not re-declared; const variables can neither be updated nor re-declared.

https://developer.mozilla.org › fr › docs › Web › JavaScript › Reference › Statements › let

L'instruction let permet de déclarer une variable dont la portée est celle du bloc courant, éventuellement en initialisant sa valeur. Exemple interactif. Syntaxe. js. let var1 [= valeur1] [, var2 [= valeur2]] [, …, varN [= valeurN]]; Paramètres. var1, var2, …, varN. Le nom de la ou des variables.

https://stackoverflow.com › questions › 22308071

The let and const. ES6 let allows you to declare a variable that is limited in scope to the block (Local variable). The main difference is that the scope of a var variable is the entire enclosing function:

https://www.w3schools.com › JS › js_let.asp

ES6 introduced the two new JavaScript keywords: let and const. These two keywords provided Block Scope in JavaScript: Example. Variables declared inside a { } block cannot be accessed from outside the block: { let x = 2; } // x can NOT be used here. Global Scope. Variables declared with the var always have Global Scope.

https://www.freecodecamp.org › news › differences-between-var-let-const-javascript

In this regard, const is different from var and let. const is used for declaring constant variables – which are variables with values that cannot be changed. So such variables cannot be redeclared, and neither can they be reassigned to other values. Attempting such would throw an error.

https://dev.to › codeparrot › javascript-var-vs-let-vs-const-key-differences-best-uses-17e7

In this blog, we've explored the key differences between var, let, and const—the three primary ways to define variables in JavaScript. We've seen how var is function-scoped and hoisted, but its quirks can lead to unintended behavior. On the other hand, let and const, introduced in ES6, offer block-scoping and greater predictability, making ...

https://developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Statements › let

Many style guides (including MDN's) recommend using const over let whenever a variable is not reassigned in its scope. This makes the intent clear that a variable's type (or value, in the case of a primitive) can never change. Others may prefer let for non-primitives that are mutated.