There are four ways to convert Java basic data types to strings
1.Captive type conversion
String str=(String)num
2. Through the form of empty string + number
String str=""+num
3. Use the static method valueOf of the String class
String str=(num)
4. First box the basic type into an object, and then call the object's toString method (this method is more troublesome, and the above three methods are recommended)
About unpacking and checkinghere