Yes, it is possible to use inline conditional statements in concatenation in JavaScript, but you need to ensure the correct use of parentheses to avoid syntax errors. The issue in your example is due to the precedence of the + operator and the ternary operator ? :.

Here is the corrected version of your code:

console.log("<b>Test :</b> " + ("null" == "null" ? "0" : "1") + "<br>");

By wrapping the conditional statement in parentheses, you ensure that it is evaluated correctly before concatenation.