Assertions

[janki tangeda]

assert Expression1:Expression2;

For the above form of assert statement, the Expression2 is required to be a value(either primitive type or reference type).

But in the example below, Expression 2 is a String object(not a reference value of String object).

assert age>0 : "The value of age cannot be negative +"age;

can anybody explain?

[Steve Morrow]

The result of that expression is a reference to a String object.

[janki tangeda]

What's the result?

[Steve Morrow]

The result is a reference to a new String object that is the concatenation of "The value of age cannot be negative " (accounting for the typo) and the String value of 'age'.