suddenly my whats contact not taking my mobile contacts

[mirfaisal]

suddenly my whats app not reading my contacts 

some r missing 

[mirfaisal]

what's APP

[pickmybrain]

Make sure you have permissions for contacts turned on for WhatsApp within settings- apps- whatsapp- permissions

[Ventor]

@mirfaisal It is as comrade @pickmybrain  has commented.
Press and hold the WhatsApp icon, you will see iboton. In Permissions grant permissions Phone and contacts. A greeting.

[Steven9761]

Also - as a suggestion, try setting your contacts' phone numbers, so that they are prefixed with the country IDD Code. For example you currently have JOHN SMITH in the UK saved as 07xxx xxxxxx - change John's number to +44 (IDD code for UK), then his number - remembering to drop the first 0. The number should now read: +44 7xxx xxxxxx. USA is +1, France is +33, etc.