Typescript exclamation mark

//Normally when you declare a member (which doesn't include undefined in it's type) 
//it has to be initialized directly or in the constructor. 
//Otherwise Typescript will raise an error.
//If you add ! after the name, TypeScript will ignore this and not show an error 
//if you don't immediately initialize it:

//Example

foo: string; // error: Property 'foo' has no initializer and is not definitely assigned in the constructor.
bar!: string; // no error

Source: stackoverflow.com

Similar codes

0 vote160 views1 answer
Check if name is unique among non-deleted items laravel
TypeScript
3 votes188 views3 answers
Typescript for loop key value pai
TypeScript
0 vote146 views2 answers
Rails precompile assets in a directory
TypeScript
4 votes153 views2 answers
When manual testing
TypeScript
-1 vote180 views1 answer
What are the components of http request
TypeScript
0 vote146 views1 answer
Based on previous make validation for required in reactive forms
TypeScript
1 vote171 views1 answer
Operator '+' cannot be applied to types 'Number' and 'Number'.
TypeScript
0 vote157 views1 answer
How to separate elements in list python
TypeScript
1 vote146 views1 answer
Ts class without implementation
TypeScript
0 vote147 views1 answer
Angular dictionary
TypeScript