to have or not to have a credit card?

I think having credit cards are really helpful. It's a great way to build your credit. But you have to control your spending, pay them on time, etc. I read somewhere that you should only charge the maximum of 30-35 percent of your total credit line. For example, if your credit line is $1000, the max you should use is $300-$350, or else your credit score will get lower. But it's a great way to build credit if you plan to purchase a car or a house down the road. Also, employers are also looking at your credit reports nowadays.

in many times is really useful, you cannot bring with you safely thousands of dollars when you travel but for the credit cards there is always a cost, in particular if they are revolving cards