如何確保對象鍵中的選擇器匹配的所有元素都具有非空值？主要只是試圖避免 if 語句中出現太多參數。我試過：var credit_map = {    "#first": "First Name",    "#middle": "Middle Name",    "#last": "Last Name",    "#email": "Email Address",    "#postalcode": "Zip/Postal Code",    "#card_name": "Name on Card",    "#card_number": "Card Number",    "#card_month": "Card Experation Month",    "#card_year": "Card Experation Year",    "#card_verification": "Card Verification Code"}for (var [key, value] of Object.entries(credit_map)) {    if ($(key).val() != null || undefined) {    }}