Javascript Equivalent to PHP Explode()

This is a direct conversion from your PHP code:

//Loading the variable
var mystr = '0000000020C90037:TEMP:data';

//Splitting it with : as the separator
var myarr = mystr.split(":");

//Then read the values from the array where 0 is the first
//Since we skipped the first element in the array, we start at 1
var myvar = myarr[1] + ":" + myarr[2];

// Show the resulting value
console.log(myvar);
// 'TEMP:data'

String.prototype.explode = function (separator, limit)
{
    const array = this.split(separator);
    if (limit !== undefined && array.length >= limit)
    {
        array.push(array.splice(limit - 1).join(separator));
    }
    return array;
};

Should mimic PHP's explode() function exactly.

'a'.explode('.', 2); // ['a']
'a.b'.explode('.', 2); // ['a', 'b']
'a.b.c'.explode('.', 2); // ['a', 'b.c']