{ionic 4} ion-select,ionic-select option

how to add functionallity for selectAll option in ion-select? .Please Explain.

Further explain your question

Filter by select All A C D E

when i select the option select all it should select all the option A,C,D,E.

simple use this

<div class="card item-icon-right"  *ngFor="let item of items" >
     <ion-checkbox *ngIf="showCheckBoxes && selectedAll" [(ngModel)]="item.id" mode="ios" [checked]="selectedAll"></ion-checkbox>

     <ion-checkbox *ngIf="showCheckBoxes && !selectedAll" [(ngModel)]="item.id" mode="ios" ></ion-checkbox>

selected values your console log


can you explain it more clearly like hows the item list is defined in ts file.
and also i want popup

<ion-select multiple="true"  mode="md" [(ngModel)]="name." placeholder="Select One">
                    <ion-select-option (click)="abc()">select All</ion-select-option>

this is the code which i am using

copy and paste your html file

             <ion-select [(ngModel)]="select" multiple="true">
                <ion-select-option>select options</ion-select-option>
                <ion-select-option>Sandeep Johnson</ion-select-option>
          <button (click)="read();">select all</button>

your ts file…
private select;

this.select = [“select options”, “Sandeep Johnson”, “India”, “Ap”, “chennai”, “Hyderabad”];

thank you. but my question is i dont want to use selectAll as button i want it as a option only ,when i select that checkbox it should auto select all the other options