package d_array;
public class ArrayBasic {
public static void main(String[] args) {
// Array = one variable storing multiple values
/*
1. What is an array?
- Handling multiple variables of the "same type" as a single bundle
ex) int mathScore =40;
int engScore =90;
int sciScore =60;
int korScore =100;
int freScore =20;
// Same type!
2. Array declaration
- Declare a variable of the desired type and use [brackets] to indicate it's an array
int[] score; // reference type, stores an address
int score[]; // you can't tell from the type alone whether it's an array
3. Not called initialization, but creation. Because it holds a value to reference. To make an address.
- To create an array, use the 'new' operator // <-- same as creating a new address,
along with specifying the array's type and size.
*/
// Declaration method 1
int[] score = new int[4]; // required, number, size // initialized with default value
// System.out.println(score);// made randomly
// System.out.println(score[0]);// initialized with default value of declared type
// System.out.println(score[1]);// initialized with default value of declared type
// System.out.println(score[2]);// initialized with default value of declared type
// System.out.println(score[3]);// initialized with default value of declared type
// System.out.println(score[4]);// starts from 0~~!!!
// Example 1) implement with for loop
// for(int i=0; i<5 ; i++){
// System.out.println("array slot "+i+":"+score[i]);
// }
for(int i=0; i<score.length ; i++){
System.out.println("array slot "+i+":"+score[i]);
}
// Example 2) assigning values to array
//0-> 0 score[0]=i*10;
//1->10 score[1]=i*10;
//2->20 score[2]=i*10;
//3->30 put score[3]=i*10;
for(int j=0; j<score.length; j++){
score[j]=j*10;
//System.out.println("array slot "+j+" value :"+score[j]);
}
//
// // Declaration method 2
// int[] score2 = new int[]{1,2,3,4}; // uninitialized slots are 0, // must have a number after ,
// System.out.println("declaration method 2"+score2[i]);
//
// // Declaration method 3
// int[] score3 = {1,2,3,4}; // when declaring with initialization, can be omitted
// System.out.println("declaration method 2"+score3[i]);
//1. Declare and create variable score2 that can store 6 subjects' scores
int[] score2 = new int[5];
//2. Initialize each slot of score2 with a random value between 0 and 100
for(int i=0; i<7;i++){
score2[i]= (int)Math.random()*100+0;
}
//3. Print all subject scores arg
System.out.println(score2[0]);
System.out.println(score2[1]);
System.out.println(score2[2]);
System.out.println(score2[3]);
System.out.println(score2[4]);
System.out.println(score2[5]);
//4. Calculate sum of subjects sum
//5. Express the subject average rounded to 2 decimal places
//6. Find the maximum among all subjects — max (do not hard-cap at 100)
//7. Find the minimum among all subjects — min (do not hard-cap at 0)
}
}
