In ruby I can use the following code to generate an array of strings from a to z:
alphabet = ('a'..'z').to_a
=> ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]
Is there a similar function call in Javascript?
Unfortunately, ECMAScript does not have a Range in its standard library. However, what you can do, is to use the Array.from factory function to construct an Array using a mapping function.
Something like this:
const alphabet = Array.from({ length: 26 }, (_, i) => i + 97).map(String.fromCharCode);
Or, without magic numbers:
const charCodeOfA = "a".charCodeAt(0), //=> 97
charCodeOfZ = "z".charCodeAt(0), //=> 122
lengthOfAlphabet = charCodeOfZ - charCodeOfA + 1, //=> 26
alphabet = Array.from({ length: lengthOfAlphabet }, (_, i) => i + charCodeOfA).
map(String.fromCharCode);
In future versions of ECMAScript, it would be nice to use do expressions to avoid polluting the namespace with those temporary helper variables:
const alphabet = do {
const charCodeOfA = "a".charCodeAt(0), //=> 97
charCodeOfZ = "z".charCodeAt(0), //=> 122
lengthOfAlphabet = charCodeOfZ - charCodeOfA + 1; //=> 26
Array.from({ length: lengthOfAlphabet }, (_, i) => i + charCodeOfA).
map(String.fromCharCode)
}
The easy way to do that is
var alphabet =[];
for(var i = "a".charCodeAt(0); i <= "z".charCodeAt(0); i++) {
alphabet.push(String.fromCharCode(i))
}
...charCodeAt... with the char values (97 & 122) for a shorter and more performant solution.
Array, but rather use theRangedirectly, since it is much more memory-efficient.