How to implement not with if statement in Ember Handlebars?

Question

I have a statement like this:

{{#if IsValid}}

I want to know how I can use a negative if statement that would look like that:

Answer 1

it can be done in multiple ways.

1 use unless

{{#unless IsValid}}

{{/unless}}

2.use if else

{{#if IsValid}}
{{else}}

{{/if}}

3.use not helper

{{#if (not IsValid)}}

{{/if}}