how to declare dynamique variable names ionic 2 - list

Question

im wondering how to dynamicaly declare variable name with ionic 2.
i want to implemet a read more function with ion-list result but to do it i need to have individual variable names.
// my ts file
import { Component } from '#angular/core';
import { NavController,Platform ,LoadingController, NavParams } from 'ionic-
angular';
import { GardeService } from '../../app/services/Garde.service';
#Component({
selector: 'page-home',
templateUrl: 'home.html'
})
export class Home {
//data:any;
public newslist: Array<Object>;
mytext:any;
prewords:any;
textpreview:any;
fulltext:any;
constructor(public data:GardeService) {}
ngOnInit()
{
this.loadnews();
this.fulltext = true;
this.textpreview = false;
}
public loadnews(){
this.newslist = [];
var map: {[key:string]:string} = {};
this.data.LoadNews().subscribe(
data => {
for(let i=0;i<data.length;i++){
//this.newslist.push(data[i]);
//console.log("news",data[i].content);
this.mytext = data[i].content.split(' ');
this.prewords = this.mytext[0] + " " + this.mytext[1] + " " +
this.mytext[2] + " " + this.mytext[3] + " " +
this.mytext[4] + " " + this.mytext[5] + " " + this.mytext[6] + " " +
this.mytext[7] + " " + this.mytext[8] + " " +
this.mytext[9] + " " + this.mytext[10] + " " + this.mytext[11] + " "
+ this.mytext[12] + " " + this.mytext[13] + " " +
this.mytext[14] + " " + this.mytext[15] + " " + this.mytext[16] + ""
+ this.mytext[17] + " " + this.mytext[18] + " " +
this.mytext[19] + " " + this.mytext[20];
//map['fulltext'+i] = true;
this.textpreview = false;
this.newslist.push({poster: data[i].poster, title: data[i].title,
img:data[i].img, content:data[i].content,
pre:this.prewords});
//console.log("les mots descriptifs",this.prewords);
}
},
err => {
console.log(err);
},
() => console.log('news loaded')
);
}
public readMore(){
this.textpreview = true;
this.fulltext = false;
}
}
// my html file
ion-col width-100 text-wrap>
<p style="text-align:justify;" color="dark" ion-text>
<span ion-text [hidden]="textpreview">{{item.pre}}</span><span
ion-text (click)="readMore()">...Lire plus</span>
<span ion-text [hidden]="fulltext">{{item.content}}</span>
</p>
</ion-col>
i want to have dynamic changing this.fulltext and this.textpreview variable names in order to do that because when i click the read more link all the content of all the ion-itens extend . i only want it to happen the place i click