Vue.js Watch Function for Voucher Group ID Changes

The given code snippet is a Vue.js component that includes a watch function called 'voucherGroupId'. This watch function is triggered whenever the 'voucherGroupId' property changes.

Inside the 'voucherGroupId' watch function, it logs the new and old values of 'voucherGroupId'. If the new value ('newV') is truthy (not null, undefined, 0, false, or empty), it updates the 'queryParams.voucherGroupId' property with the new value and then calls the 'getList' method.

The 'getList' method checks if the 'queryParams.voucherGroupId' is not null. If it's not null, it creates a 'param' object with the 'voucherGroupId' property set to the value of 'this.$props.voucherGroupId'. It then calls the 'getVoucherGroup' function with the 'param' object as a parameter. Once the promise is resolved, it logs the response ('res') to the console.

If the 'queryParams.voucherGroupId' is null, it logs the message 'vouchergroupid is null' to the console.