Inscrivez-vous ou connectez-vous pour rejoindre votre communauté professionnelle.
According to EcmaScript language specification, the addition operator either performs string concatenation or numeric addition.
The production result = leftPrimitive + rightPrimitive is evaluated as follows :
I type of leftPrimitive is string or type of right primitive is string, result is the result of concatening of leftPrimitive followed by rightPrimitive.
Therefore, the answer is : The datatype will be "string".