How to create dynamic href in react render function?
Use string concatenation:
href={'/posts/' + post.id}
The JSX syntax allows either to use strings or expressions ({...}) as values. You cannot mix both. Inside an expression you can, as the name suggests, use any JavaScript expression to compute the value.
You can use ES6 backtick syntax too
<a href={`/customer/${item._id}`} >{item.get('firstName')} {item.get('lastName')}</a>
More info on es6 template literals