ng-class sets the class based on key: value

function ctr($scope){
   $scope.test =“classname”;
}



<p class=”{{test}}”></p>



function Ctr($scope) { 
    $scope.isActive = true;
}



<p ng-class="{true: 'active', false: 'inactive'}[isActive]">
</p>



function Ctr($scope) { 

}



<p ng-class {'selected': isSelected, 'car': isCar}">
</p>

I did a project today and found that there is another way to write, which cannot be learned from books.

ng-class="{'IM_selected':(status.currTalkTo.FRIENDID==item.FRIENDID)}"

This is the syntax of js, explained as follows: If status.currTalkTo.FRIENDID == item.FRIENDID is equivalent, IM_selected will be displayed, otherwise it will not be displayed. This syntax is often used in projects to obtain the current page.