Logic = hard

 d.results.length > 0 ? this.existingAddresses = true : this.existingAddresses = false

Variable abuse

let checkForHighlight = true;

for (let rows of this.tableBody.nativeElement.children)
{
    if (checkForHighlight && rows.classList.contains('alert-warning'))

    {
        checkForHighlight = false;
    }
}

if (!checkForHighlight)

{
    this.showQuantityWarning = true;
}

else

{
    this.showQuantityWarning = false;
}