These are ways to strengthen a country's currency. But i have one question in mind that if one country's currency is more than another country then also its economy will be stronger?
No. You have to ask yourself: what is the "strength" of that economy.
A strong economy can also have a downgraded currency.
(like China/Japan for example)
More important is the economical background and the "business model" of the country in which the currency is embedded.