Angular Built-in directives
This example demonstrates how Angular expressions are evaluated when using type="text" and type="number" for the input element. Consider the following controller and view:
When using + in an expression bound to text input, the operator will concatenate the strings (first example), displaying 55 on the screen*.
When using + in an expression bound to number input, the operator return the sum of the numbers (second example), displaying 10 on the screen*.
* - That is until the user changes the value in the input field, afterward the display will change accordingly.