问题
I want to do something like:
var list = [1,2,3,4,5]
if(2 in list){
return true
}
from a ng-class, so I tried:
ng-class="this.id in list ? 'class-1' : 'class-2' ">
But doesn't worked, throws an error
Syntax Error: Token 'in' is an unexpected token at ...
回答1:
For arrays you'd use indexOf, not in, which is for objects
if ( list.indexOf(this.id) !== -1 ) { ... }
so
ng-class="{'class-1' : list.indexOf(this.id) !== -1, 'class-2' : list.indexOf(this.id) === -1}"
回答2:
Look at the following code:
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.8/angular.min.js"></script>
<style>.blue{background:blue;}</style>
</head>
<body ng-app="myApp" ng-controller="myCtrl">
<p ng-class="{blue:present}">This is a paragraph. </p>
<script>
//Module declaration
var app = angular.module('myApp',[]);
//controller declaration
app.controller('myCtrl', function($scope){
$scope.present = false;
$scope.colors = ['red','green','blue'];
angular.forEach($scope.colors, function(value, key){
if(value == "green"){
$scope.present = true;
}
});
});
</script>
</body>
</html>
Hope, it helps your problem!
来源：https://stackoverflow.com/questions/36802586/how-to-check-if-something-is-in-array-from-ng-class