Constants in Javascript

Created: 2022-10-15

Use const when you can, and use let when you have to.

const count = 1;
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Note Important to read
that although a constant in JavaScript must always name the same value, you can change the content of the value that it names. This isn't a useful distinction for simple types like numbers or booleans, but consider an object:

const bird = { species : 'Kestrel'};
console.log(bird.species);  // "Kestrel"
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You can update, add, or remove properties of an object declared using const, because even though the content of the object has changed, the constant is still pointing to the same object:

bird.species = 'Striated Caracara';
console.log(bird.species);  // "Striated Caracara"
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• case sensitive (myage is different from myAge)
• no numbers at start of variables
• Don't use underscores at the start of variable names — this is used in certain JavaScript constructs to mean specific things, so may get confusing.
• Dynamically typed language