dataArray.push( `${ currentObject.config.productPrefix ? currentObject.config.productPrefix : "" } ${constant.getProductData(currentObject.config.prodId).displayName}` );

You can use the following code to get the type of a variable:
const { type } = typeof myVariable;

You can use it like this:
const { type } = typeof myVariable;
if (type === 'number') {
    // do something
}

A:

You can use typeof to get the type of a variable:
typeof myVariable;