How should I escape the comma "," while forming the URL in lightning aura component

Question

In my lightning aura component: I am using below code to open a pop up for New user record creation and I am passing default field values to be pre-populated from another object, I am able to get the pop up fine with pre-populated values. Only problem is when I click the save button I get error saying "No access to field Billing. Either the field was removed from the entity or access to this field was removed.", For example if the title field has value "Junior Coordinator, Billing" then the comma between Coordinator, Billing is being considered as the start of another parameter.

            var pageReference = {
                "type": "standard__objectPage",
                "attributes": {
                    objectApiName: "User",
                    actionName: "new"
                },
                state: {
                    defaultFieldValues : 'FirstName='+component.get('v.ContactFirstName')+',title='+component.get('v.title')+',LastName='+component.get('v.ContactLastName')
                    }
                };

Answer 1

This is covered in the documentation. Use encodeDefaultFieldValues to get the correct encoding:

import { encodeDefaultFieldValues } from 'lightning/pageReferenceUtils';

...

const defaultValues = encodeDefaultFieldValues({
    FirstName: 'Morag',
    LastName: 'de Fault',
    LeadSource: 'Other'
});

...

state: {
    defaultFieldValues: defaultValues
}