The {0} {1} {2} his {3} off

<div *ngFor="let question of questionsArray">
     ---- some stuff ----
    <div [innerHTML]="createQuestion(question)"></div>
     ---- some stuff ----
</div>

createQuestion(question: string): SafeHtml {
    let innerHtml = '';
    let words = question.split(' ');

    for (let index = 0; index < words.length; index++) {
        const element = words[index];
        if (element.indexOf('{') >= 0) {
            innerHtml += '<input type="text" name="test"></input>';
        } else {
            innerHtml += element;
        }
    }

    return this.sanitizer.bypassSecurityTrustHtml(innerHtml);
}

constructor(private sanitizer: DomSanitizer) {}