Ionic app with xcode

when i upload my ionic app ios platform to xcode and it build successfully then ran it on target device every thing fine but when i change anything in my code then i rebuild the platform again after deleting the existing platform but the code changes does not reflect when i ran it again on a target device

Ionic:

ionic (Ionic CLI) : 4.2.1
Ionic Framework : ionic-angular 3.9.2
@ionic/app-scripts : 3.2.0

Cordova:

cordova (Cordova CLI) : 8.1.2
Cordova Platforms : ios 4.5.5

System:

ios-deploy : 1.9.4
ios-sim : 5.0.13
NodeJS : v9.8.0
npm : 5.6.0
OS : macOS High Sierra
Xcode : Xcode 9.4.1 Build version 9F2000