Python (as of 1990): xs[-1]
Ruby (as of 1995): xs[-1]
JS (also as of 1995): xs[xs.length - 1]
JS (as of 1999, probably an uncommon idiom): xs.slice(-1)[0]
JS (as of 2015): var [x] = xs.slice(-1)
Python or Ruby:
g(f()[-1])
JavaScript, 1995:
var xs = f()
var x = xs[xs.length - 1]
g(x)
JavaScript, 1999:
g(f().slice(-1)[0])
JavaScript, 2015:
var [x] = f().slice(-1)
g(x)
ruby-doc.org/core-2.5.1/Enu…