Obtaining the First Pupil

Checking JS properties without mid-function returns

by nevkatz

HTML

<div id="root">
  
</div>

JavaScript

let myTeacher = {
    data:{ 
       classes: [{
             classId:123,
             pupils:[
                {
                    firstName:'Nevin',
                    lastName:'Katz'
                }
             ]
       }]
    }
};


function getFirstPupil(teacher) {
     if (teacher && teacher.data && teacher.data.classes) {
       
       if (teacher.data.classes.length > 0) {
          let class_obj = teacher.data.classes[0];
          
          if (class_obj.pupils) {
            return class_obj.pupils[0] || null;
          }
       }
     }
     return null;
}

function init() {
 let test1 = document.querySelector('#root');
 
 let pupil_obj = getFirstPupil(myTeacher);

 test1.textContent = pupil_obj.firstName;
 
}
init();