<div [ngSwitch]="num">
    <div *ngSwitchCase="0"> 0</div>
    <div *ngSwitchCase="1"> 1</div>
    <div *ngSwitchDefault>默认的</div>
</div>

switch(num){
    case 0: return 0;
    case 1: return 0;
    default: return '默认的';
}

<div [ngSwitch]="num">
    <div *ngSwitchCase="0"> 0</div>
    <div *ngSwitchCase="(num === 1 || num===4) ? num : ''"  > 1或者4</div>
    <div *ngSwitchDefault>默认的</div>
</div>

switch(num){
    case 0: return 0;
    case 1:
    case 4: return '1或4';
    default: return '默认的';
}