What is template expression in angular 6? Explain with a syntax.

A template expression produces a value in Angular within double curly braces {{ }}. It executes the expression and assigns it to a property of the particular binding and the target can be an HTML element, a component, or a directive.

In terms of syntax, it is much similar to that of Javascript. Most of the JavaScript expressions are legal template expressions, with a few exceptions.

You can't use JavaScript expressions that have or promote side effects, including:

Assignments (=, +=, -=, ...)
Operators like new, typeof, instanceof, etc.
Chaining expressions with ; or ,
With increment and decrement operators ++ and --
Most of the ES2015+ operators