JSFiddle - React, Tailwind, and code Playground

by neonDog

JavaScript

const createPlaceholders = function(num, len) {
    const arr1 = new Array(num).fill('?');
    const str1 = '(' + arr1.join(',') + ')';
    const arr2 = new Array(len).fill(str1);
    return arr2.join(', ');
};

document.body.innerHTML = 'INSERT VALUES (x, y, z) SET ' + createPlaceholders(5,8);