//Other Form Controls
 empCode:[this.userFormDetails.userId],
 empName:[this.userFormDetails.name],
 pensionType:[''],
 fhName:[
          ()=>{
return this.userFormDetails.gender=="Male"? this.userFormDetails.fatherName:this.userFormDetails.spouseName
}],
.
//Rest of the controls

()=>{ ( **<--addition parenthesis**
return this.userFormDetails.gender=="Male"? this.userFormDetails.fatherName:this.userFormDetails.spouseName
)}

fhName:[{
     value: ()=>{
                 return this.userFormDetails.gender=="Male"?
                 this.userFormDetails.fatherName:this.userFormDetails.spouseName
                },
                disabled:false
             }
            ]