Student's names(String[]) and corresponding marks(int[]) are stored in different arrays.
How may I iterate over both arrays together using for each loop in Java ?
void list() {
for(String s:studentNames) {
System.out.println(s); //I want to print from marks[] alongside.
}
}
One trivial way could be using index variable in the same loop. Is there a good way to do?
You need to do it using the regular for loop with an index, like this:
if (marks.length != studentNames.length) {
... // Something is wrong!
}
// This assumes that studentNames and marks have identical lengths
for (int i = 0 ; i != marks.length ; i++) {
System.out.println(studentNames[i]);
System.out.println(marks[i]);
}
A better approach would be using a class to store a student along with his/her marks, like this:
class StudentMark {
private String name;
private int mark;
public StudentMark(String n, int m) {name=n; mark=m; }
public String getName() {return name;}
public int getMark() {return mark;}
}
for (StudentMark sm : arrayOfStudentsAndTheirMarks) {
System.out.println(sm.getName());
System.out.println(sm.getMark());
}
The underlying problem is actually that you should tie both of the arrays together and iterate across just one array.
Here is a VERY simplistic demonstration - you should use getters and setters and you should also use a List instead of an array but this demonstrates the point:
class Student {
String name;
int mark;
}
Student[] students = new Student[10];
for (Student s : students) {
...
}
If them both have the same size, I would write:
for(int i = 0; i<marks.length; i++) {
String names= studentNames[i]
int mark = marks[i];
}
The other way is to use a verbose for loop statement such as;
int i,j;
for(i = 0, j=0; i<= student.length-1 && j <=grades.length-1; i++,j++)
{
...
}
i. There will never be a case where i != j. In which case, it's not verbose, and is honestly just the correct way to do it.Going with Sergey Kalinichenko's something is wrong:
if (marks.length != studentNames.length) {
... // Something is wrong!
}
Iterator<Integer> marks_ = java.util.Arrays.asList(marks).iterator();
// This assumes that studentNames is no longer than marks
for (String name: studentNames)
System.out.println(name + ": " + marks_.next());
for(String s : studentNames, int g : grades) {...}