Javascript 检查角度模板中的值是否不为空且不为空？
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Check if value is not empty and not null in angular template?
提问by user3063182
How do I check if value is not empty and not null.
如何检查值是否不为空且不为空。
in Controller:
$scope.data.variable = 'some valid data';
在控制器中：
$scope.data.variable = 'some valid data';
<div ng-if="data.variable != ''">something else</div>
<div ng-if="data.variable != ''">something else</div>
Thanks
谢谢
回答by A.B
since both null and empty are falsy values
因为 null 和 empty 都是假值
div.variable if notnullor emptywill evaluate to trueand if either of nullor emptywill evaluate to false
div.variable 如果notnull或empty将评估为true，如果其中之一null或empty将评估为假
<div ng-if="data.variable">something else</div>
回答by user3063182
I suggest you have such a function is your controller:
我建议你有这样一个功能是你的控制器：
$scope.isEmpty = function(value){
return (value == "" || value == null);
};
And your HTML:
还有你的 HTML：
<div ng-if="!isEmpty(data.variable)">something else</div>
If this function will be useful in many of your pages I suggest you put it on the $rootScope, so that it's recognized in the entire application.
如果此功能在您的许多页面中都有用，我建议您将其放在 $rootScope 上，以便在整个应用程序中都能识别它。
回答by Ashesh
From what it looks like in your case, I think you're expecting either an empty string, or null. To write a reasonable check, I would consider it best to go about it like this;
从您的情况来看，我认为您期望的是一个空字符串，或者null. 为了写出合理的支票，我认为最好这样做；
$scope.isValid = function(val) {
var ret = true;
if (angular.isString(val)) {
ret = ret && (val.length > 0);
}
return ret && (val !== null);
}
