Narcissistic decimal number: Difference between revisions

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@@ Line 1,199: / Line 1,199: @@
 =={{header|JavaScript}}==
+===ES5===
 {{trans|Java}}
 <lang javascript>function isNarc(x) {
@@ Line 1,226: / Line 1,227: @@
 {{out}}
 <pre>"0 1 2 3 4 5 6 7 8 9 153 370 371 407 1634 8208 9474 54748 92727 93084 548834 1741725 4210818 9800817 9926315"</pre>
+===ES6===
+<lang JavaScript>(() => {
+    'use strict';
+    // digits :: Int -> [Int]
+    const digits = n => n.toString()
+        .split('')
+        .map(x => parseInt(x, 10));
+    // pow :: Int -> Int -> Int
+    const pow = Math.pow;
+    // isNarc :: Int -> Bool
+    const isNarc = n => {
+        const
+            ds = digits(n),
+            len = ds.length;
+        return ds.reduce((a, x) => {
+            return a + pow(x, len);
+        }, 0) === n;
+    };
+    // until :: (a -> Bool) -> (a -> a) -> a -> a
+    const until = (p, f, x) => {
+        let v = x;
+        while (!p(v)) v = f(v);
+        return v;
+    };
+    return until(
+            x => x.narc.length > 24,
+            x => ({
+                n: x.n + 1,
+                narc: (isNarc(x.n) ? x.narc.concat(x.n) : x.narc)
+            }), {
+                n: 0,
+                narc: []
+            }
+        )
+        .narc
+        .join('\n');
+})();</lang>
+{{Out}}
+<pre>0
+1741725
+4210818
+9800817
+9926315</pre>
 =={{header|jq}}==