How to disable a checkbox based on conditions in angular 6?

ng-disabled is AngularJS syntax. You can use [disabled] input for disable checkboxes.

<input [disabled]="isDisabled" = type="checkbox" id="Checkbox0" name="cCheckbox0" class="custom-control-input" (change)="checkSelected(checkBox[0].label)">

in .ts isDisabled : boolean;

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Optional thing

You can use Angular Material for your developments. because it has many advantages. And also it has well defined API.

<mat-checkbox> provides the same functionality as a native <input type="checkbox"> enhanced with Material Design styling and animations.

Angular Material

For Angular 2+, you can enable / disable the checkbox by setting the disabled attribute on the input type=checkbox

Use: [attr.disabled]="isDisabled ? true : null"

Note here that [attr.disabled]="isDisabled alone will not work. You will need to explicitly set disabled attribute to null for removing disabled attribute from the disabled checkbox.

<input type="checkbox" [attr.disabled]="isDisabled ? true : null" />