web喚起whatsapp客戶端通過號碼聯系

如果安裝了whatsapp客戶端，只需跳轉

window.location.href = "https://wa.me/號碼";

如果有區號則只需在前面直接加區號，例如加香港區號：

https://wa.me/852XXXXXXXX

if (window.navigator.userAgent.match(/(iPhone|iPod|iPad);?/i)) {
       window.location.href = "https://wa.me/號碼";
       setTimeout(function () {
            window.location.href = "https://itunes.apple.com/us/app/whatsapp-messenger/id310633997?mt=8";
            window.location.href = "https://itunes.apple.com/us/app/whatsapp-messenger/id310633997?mt=8";
        }, 2000);
    } else if (window.navigator.userAgent.match(/android/i)) {
        window.location.href = "https://wa.me/號碼";;
        setTimeout(function () {
            window.location.href = "https://play.google.com/store/apps/details?id=com.whatsapp";
        }, 2000)
    }

或者可以到 http://www.conversabit.com/wasap.js/ 提供的小插件自動適配

html：
<span data-whatsapp="5215585420898">This will be clickable on mobile</span>

javascript：
wasap.init()

插件還能配合vue應用，具體查看官網