WhatsApp releases some updates every month. If it is said that WhatsApp is the app that releases the most updates then it will not be wrong. WhatsApp is going to release one of the most useful features soon after which you will not have to try to save the number. WhatsApp is testing QR code support on the beta version of Android and iOS.
After which users will be able to scan the QR code of the new user and save their number, although no announcement has been made about the date of release of this feature for all. The QR code based number saving feature is currently beta version 2.20 of Android. The beta version of 171 and iPhone can be viewed at 220.127.116.11. Testing of this feature has been reported by WABetaInfo in its report.
According to WABetaInfo the QR code will be found inside the profile setting. Scanning that QR code will show the users' mobile number. Note that a few days ago, WhatsApp has released an update after which eight people can simultaneously do video calling, although this feature is currently only for iOS users. Android users will have to wait for now.