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I usually just do just enough javascript, but didn't know the difference between let and var, not it makes sense. the explanation of reduce made sense too.
by jlebrech 9y ago
I usually just do just enough javascript, but didn't know the difference between let and var, not it makes sense. the explanation of reduce made sense too.
- Fifer82 9y agoI always use `const` unless i can't otherwise `let`. There is no place for `var` although everyone has an opinion this has always worked for me.
- Mateon1 9y ago`let` is block scoped, while `var` is function scoped. Essentially: function do_something() { if (true) { var x = 42; let y = 42; } console.log(x); // 42 console.log(y); // Reference error: y is not defined } It's extremely useful in for loops: for (var i = 0; i < 5; i++) { setTimeout(function () { console.log(i); }); // => 5, 5, 5, 5, 5 } for (let i = 0; i < 5; i++) { setTimeout(function () { console.log(i); }); // => 0, 1, 2, 3, 4 }
- jlebrech 9y agothat makes a lot of sense, I used to just make a brand new unique variable for loops