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Zevan Rosser
Zevan Rosser

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Array Sum Golfed

#javascript #codegolf 
a = [1, 2, 3, 6, 9]; sum = eval(a.join`+`); console.log(sum); // outputs 21
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Lately doing stuff with eval has been pretty fun. This does:

eval('1+2+3+6+9');
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I used a more dynamic version of this recently:

const f = (o, ...a) => eval(a.join(o));
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I had an idea for parsing Polish notation (+ 10 10) by just transforming s-expressions like that into function calls: f('+', 10, 10)... I've always liked Polish notation...

Here is the little Polish notation thing (warning extremely hacky)

const f = (o, ...a) => eval(a.join(o)); const polish = eq => eval( eq.replace(/\s+/g, ' ') .replace(/(\))\s([0-9])/g, '$1,$2') .replace(/([0-9]+)[^\)]/g, '$1,') .replace(/\(\s?([\+\-\*\\/])/g, 'f(`$1`,') ); console.log(polish('(* 2 2)')); console.log(polish('(* 2 2 (+ 3 2 1))')); console.log(polish('(- 10 3)')); console.log(polish('(/ (+ 10 10 (* 2 2)) 3)'));
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See more stuff like this over @ Snippet Zone

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