Mastering Nested Loops: Pushing Entries into a Result Array with Ease

Welcome to the world of nested loops, where complexity meets creativity! In this article, we’ll tackle a fascinating challenge: how to push entries into a result array from the deepest nested loop, while also pushing an entry when the deepest loop is not reached. Buckle up, folks, as we’re about to embark on a thrilling adventure!

The Problem Statement

Imagine you’re working on a project that involves iterating through multiple layers of data, where each layer has its own set of rules and conditions. Your task is to collect specific data points and store them in a result array. Sounds simple, right? Well, things get interesting when you need to push entries into the result array from the deepest nested loop, while also accounting for scenarios where the deepest loop is not reached.

Let’s consider an example to illustrate this problem. Suppose we have a dataset of students, each with multiple subjects, and each subject having multiple assignments. We want to create a result array that contains the student’s name, subject name, and assignment details. The catch: we need to push an entry into the result array even if the student doesn’t have any assignments for a particular subject.

Understanding the Nested Loop Structure

students = [
  {
    name: 'John',
    subjects: [
      {
        name: 'Math',
        assignments: [
          { id: 1, grade: 90 },
          { id: 2, grade: 85 }
        ]
      },
      {
        name: 'Science',
        assignments: []
      }
    ]
  },
  {
    name: 'Jane',
    subjects: [
      {
        name: 'English',
        assignments: [
          { id: 1, grade: 95 }
        ]
      }
    ]
  }
];

In this example, we have an array of students, each with an array of subjects, and each subject having an array of assignments. Our goal is to push entries into the result array from the deepest nested loop (assignments) while also accounting for subjects with no assignments.

The Solution: A Step-by-Step Guide

Now that we understand the problem and the nested loop structure, let’s create a solution step-by-step:

Step 1: Initialize the Result Array

First, we need to initialize an empty array to store our result:

const result = [];

Step 2: Iterate Through Students

Next, we’ll iterate through the students array using a for loop:

for (let i = 0; i < students.length; i++) {
  const student = students[i];

Step 3: Iterate Through Subjects

Inside the student loop, we'll iterate through the subjects array using another for loop:

for (let j = 0; j < student.subjects.length; j++) {
  const subject = student.subjects[j];

Step 4: Check for Assignments

Now, we'll check if the subject has any assignments. If it does, we'll iterate through the assignments array using a third for loop:

if (subject.assignments.length > 0) {
  for (let k = 0; k < subject.assignments.length; k++) {
    const assignment = subject.assignments[k];
    // We'll push an entry into the result array from the deepest loop
    result.push({
      studentName: student.name,
      subjectName: subject.name,
      assignmentId: assignment.id,
      grade: assignment.grade
    });
  }
} else {
  // If the subject has no assignments, we'll push an entry with default values
  result.push({
    studentName: student.name,
    subjectName: subject.name,
    assignmentId: null,
    grade: null
  });
}

Step 5: Loop Through All Students and Subjects

Finally, we'll loop through all students and subjects using our nested loops:

for (let i = 0; i < students.length; i++) {
  const student = students[i];
  for (let j = 0; j < student.subjects.length; j++) {
    const subject = student.subjects[j];
    if (subject.assignments.length > 0) {
      for (let k = 0; k < subject.assignments.length; k++) {
        const assignment = subject.assignments[k];
        result.push({
          studentName: student.name,
          subjectName: subject.name,
          assignmentId: assignment.id,
          grade: assignment.grade
        });
      }
    } else {
      result.push({
        studentName: student.name,
        subjectName: subject.name,
        assignmentId: null,
        grade: null
      });
    }
  }
}

The Result: A Comprehensive Array

After executing the nested loops, our result array will contain the following entries:

Student Name	Subject Name	Assignment ID	Grade
John	Math	1	90
John	Math	2	85
John	Science	null	null
Jane	English	1	95

Notice how we've pushed entries into the result array from the deepest nested loop (assignments), while also accounting for subjects with no assignments.

Conclusion

In this article, we've mastered the art of pushing entries into a result array from the deepest nested loop, while also pushing an entry when the deepest loop is not reached. By following the step-by-step guide, you should now be able to tackle complex nested loop challenges with confidence. Remember to initialize your result array, iterate through each layer of data, check for conditions, and push entries accordingly. Happy coding!

Keywords: nested loops, array manipulation, data iteration, conditional statements, push entries into array.

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