Share via Whatsapp in ios

There are two method to share via whatsapp

1. URL scheme
2. Document Interaction API

If you want to go with URL Scheme
then here is example.

/**Just open whatsapp*/

NSURL *whatsappURL = [NSURL URLWithString:@"whatsapp://app"];
if ([[UIApplication sharedApplication] canOpenURL: whatsappURL]) {
    [[UIApplication sharedApplication] openURL: whatsappURL];
}

/** Send Hello World! to any contact/group*/

NSURL *whatsappURL = [NSURL URLWithString:@"whatsapp://send?text=Hello%2C%20World!"];
if ([[UIApplication sharedApplication] canOpenURL: whatsappURL]) {
    [[UIApplication sharedApplication] openURL: whatsappURL];
}

/** Send message to selected contact*/

NSURL *whatsappURL = [NSURL URLWithString:@"whatsapp://abid?/*Address Book ID*/"];
if ([[UIApplication sharedApplication] canOpenURL: whatsappURL]) {
    [[UIApplication sharedApplication] openURL: whatsappURL];
}

And if you want to go with Document Interaction API then check whatsapp documentation.