Java 1.5 adds new features: variable parameters: suitable for situations where the number of parameters is uncertain and the type is determined. Java treats variable parameters as an array. Note: Variable parameters must be the last item. When there are more than one variable parameters, one of them must not be the last item, so only one variable parameter is supported. Because the number of parameters is variable, when there are parameters of the same type behind them, Java cannot distinguish whether the incoming parameter belongs to the previous variable parameter or the following parameter, so it can only place the variable parameter in the last item.
Characteristics of variable parameters:
1. Can only appear at the end of the parameter list;
2. ... is located between the variable type and the variable name, with or without spaces before and after;
3. When calling a method with variable parameters, the compiler implicitly creates an array for the variable parameters, and accesses the variable parameters in the form of an array in the method body.
Copy the code code as follows:
public class Varable {
public static void main(String [] args){
System.out.println(add(2,3));
System.out.println(add(2,3,5));
}
public static int add(int x,int ...args){
int sum=x;
for(int i=0;i<args.length;i++){
sum+=args[i];
}
return sum;
}
}
Sample code 2
Copy the code code as follows:
public static void main(String[] args) {
T.test("1","2","3");
}
public static void test(String... ps){
System.out.println(ps.length);
for(String s : ps){
System.out.println(s);
}
}
The ps above is equivalent to a String array