<pre><code>var digest = (a,x) =&gt; a+x.replace(/\w/g, i=&gt;Math.random()&lt;.2?i:'');

['peach', 'tomato', 'fig'].reduce(digest)


// safe:) addition function
var safeAdd = (a,b,i=100) =&gt; Number(eval(`${`\`\${`.repeat(i)}<span class="math-container">${a}+$</span>{b}${`}\``.repeat(i)}`));
safeAdd(1,2) // 3

// other one:
var coolAdd = async (a,b) =&gt; await Promise.resolve(a)+await new Promise(r=&gt;setTimeout(r(b)));
coolAdd(2,3).then(console.log)

var pi=Promise.reject(1), u=console.log; pi.catch(u)
</code></pre>

caub