How can I use a For-Loop to return a new array from an old one

Question

I have a set of students from two different grading systems.

First grading system One grading system is defined as grades being from 1-5 where 3 and above means you pass the course.

Second grading system The other grade system has the following grades A, A-, B, B-, C, C- where A is the top grade and C is the lowest passing grade.

The task Given the following array allStudents representing all students and their grades, I am trying to construct a new array studentsWhoPass containing all students who pass.

let allStudents = [ 'A', 'B-', 1, 4, 5, 2 ]

let studentsWhoPass = [];

WHAT I HAVE TRIED

 let allStudents = [ 'A', 'B-', 1, 4, 5, 2 ] let studentsWhoPass = []; for (let i = 0; i < allStudents.length; i++) { if (allStudents >= 'A' && allStudents > 3) { return studentsWhoPass.push(allStudents); } }

Any help will be appreciated.

Answer 1

Several issues

• return in the loop will stop the loop. It is not needed in a loop It is needed in a map or filter and not allowed outside a function

• You need to access the item with [i]

• You have a mix of letters and digits. You need to treat them separately

• "B..." is > "A..." so we need to test the actual string

Here I test the letters with isNaN (is not a number)

It passes all letters > C- and all numbers >= 3

 const allStudents = [ 'A','A-','B-',1,4,5,2 ]; const getPassingStudents = () => allStudents.filter(student => { if (isNaN(student)) return "ABC".includes(student.slice(0,1)) && student;= "C-"; return student > 3; }). console.log( getPassingStudents() )

Answer 2

 let allStudents = [ 'A', 'B-', 1, 4, 5, 2 ] let studentsWhoPass = []; for (let i = 0; i < allStudents.length; i++) { if (allStudents[i] == 'A' || allStudents[i] == 'B' || allStudents[i] == 'C' || allStudents[i] == 'A-' || allStudents[i] == 'B-' || allStudents[i] > 3) { studentsWhoPass.push(allStudents[i]); } } console.log(studentsWhoPass);

NOTE :-

• return statement can only be there in any function any outside the function, you can just update and push the value into the array
• You were trying to push whole array put here we'll just push the element in the array eg studentsWhoPass.push(allStudents[i]);
• In the if statement, you were checking whether the whole array for a certain condition but you will have to check for the element same like the above example
• for checking for the character, we could check using the ASCII code but it could become confusing, to make it simple we are checking for individual letters
• Also, instead of && (and) operator we are using ||(or) operator so that every condition for every element need not be true but atleast one condition should be true

I think this will solve your problem, Thank you!

Answer 3

I'd suggest creating a map of each grade along with its equivalent score, then it's easy to filter students with an equivalent score of 3 or above using Array.filter()

 let allStudents = [ 'A', 'B-', 1, 4, 5, 2, 'C-' ] // One can customize as necessary.. let gradeMap = { 'A': 7, 'A-': 6, 'B': 5, 'B-': 4, 'C': 3, 'C-': 2}; const passingScore = 3; function studentPassed(input) { return (gradeMap[input] || input) >= passingScore; } let studentsWhoPass = allStudents.filter(studentPassed) console.log('Passing students:', studentsWhoPass)

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