error Cannot read property ‘split’ of undefined

Question

I work on angular 7 

I get error 

ERROR TypeError: Cannot read property 'split' of undefined
    at managelocations.component.ts:120
    at Array.forEach ()
    at SafeSubscriber._next (managelocations.component.ts:117)
    at SafeSubscriber.push../node_modules/rxjs/_esm5/internal/Subscriber.js.SafeSubscriber.__tryOrUnsub (Subscriber.js:196)
    at SafeSubscriber.push../node_modules/rxjs/_esm5/internal/Subscriber.js.SafeSubscriber.next (Subscriber.js:134)

error come from this line below :

var loc = this.dataLocation.split(',');

console.log (dataLocation); 

print  

5.2951916,100.28825170000005 

How to solve this problem