Angular2 How to Handle null value in .find methode - angular2-forms

Question

Here i wrote simple .find method its finding my data well but if that record is not available then its displying 1st Record
public _pagedItems : any;
someval(value){
if(value.length>=5){
this._pagedItems= this.allItems.find(e=>e.uniqueid = value);
this.pagedItems=[];
this.pagedItems.push(this._pagedItems);
}
if my uniquId is not avaible then its should display Nodata OR Null

Answer 1

Here is an example for handle null and undefined and return no data like
Your code is looking wrong. Your are code using (=) symbol. So change (==).
The difference between = and == (=) equal symbol is assigning value (==) symbol is comparing a value
For more proper example here,
public _pagedItems : any[]=[];
someval(value:string){
if(!this.isObjNull(value) && !this.isObjNull(this.allItems) && this.allItems.length>0){
if(value.length>=5){
if(this.allItems.find(e=>e.uniqueid ==value)){
//you need one data use find
this._pagedItems=this.allItems.find(e=>e.uniqueid == value);
//you need multiple data use filter
this._pagedItems = this.allItems.filter(e=>e.uniqueid == value);
}
//here Iam logged final variable
console.log("Final Paged Items",this._pagedItems);
}
}
}
//here is the method check null and undefined.
isObjNull(data){
If(data!=null && data!=undefined){
return true:
}else{
return false;
}
}
You can handle html part like this
<ng-container *ngIf="_pagedItems; else noData">
<ng-container *ngIf="_pagedItems.length>0; else noData">
<!-- do you logic here.like *ngFor -->
</ng-container>
</ng-container>
<ng-template #noData>
<p>No data found</p>
</ng-template>
That's all let try this once. If any error please let me know.
Note:- here Iam used sample variable please replace your actual variable.
For comparison related more thing visit here.
Difference between == and === in JavaScript