When it comes to iterating through arrays in nodejs

Question

When it comes to iterating through arrays in nodejs

Can someone assist me with using a for loop on an array to search for titles? I have a basic ADD TODO form input that submits and adds todos or titles to the array:

  todos.push({ title: req.body.add_todo_input, complete: false });

I am pushing user input/todos into the array with this code. Then, I am using EJS to display the result on the webpage <%= todos.title %>. I thought about implementing a for loop that iterates through the array to add conditional if statements checking if any of the titles in the array match the input. If there is a match, I want to prevent pushing the todos and instead log the message ("Error: TODO already exists").

javascript arrays

Answer 1

Answer №1

If you want to search for specific titles in an Array, you can utilize the includes() method.

const animals = [{ title: 'lion'}, { title: 'elephant'}, { title: 'monkey'}];

console.log(animals.includes(a=> a.title === 'elephant'));
// expected result: true

Answer 2

If you want to search for specific titles in an Array, you can utilize the includes() method.

const animals = [{ title: 'lion'}, { title: 'elephant'}, { title: 'monkey'}];

console.log(animals.includes(a=> a.title === 'elephant'));
// expected result: true

Answer 3

Answer №2

To accomplish this task, you can utilize the some() method. When using some, it will return true if the provided function evaluates to true for any element in the array, otherwise it will return false.

 const addTodoItem = (todoList, newTask) => {
  const isTaskPresent = todoList.some((task) => task.title === newItem);
  if (isTaskPresent) {
    console.log(' Error: Task already exists ');
    return todoList;
  }
  return todoList.concat({ title: newTask, completed: false });
};

todos = addTodoItem(todos, req.body.new_task_input);

Answer 4

To accomplish this task, you can utilize the some() method. When using some, it will return true if the provided function evaluates to true for any element in the array, otherwise it will return false.

 const addTodoItem = (todoList, newTask) => {
  const isTaskPresent = todoList.some((task) => task.title === newItem);
  if (isTaskPresent) {
    console.log(' Error: Task already exists ');
    return todoList;
  }
  return todoList.concat({ title: newTask, completed: false });
};

todos = addTodoItem(todos, req.body.new_task_input);

Answer 5

Answer №3

Discover which todos with specific titles are included in an array as shown below

let todos = [{title: "abc"}, {title: "def"}]
function addTodo(title) {
  let found = todos.find(item => item.title == title)
  if (found) {
    console.log("todo already exists")
  } else {
    todos.push({title: title})
  }
}

Use the above function when adding new items to the todo list

addTodo("abc")

Since "abc" is already present, an error will be shown in the console

addTodo("xyz")

This time, "xyz" will be added to the todo list

Answer 6

Discover which todos with specific titles are included in an array as shown below

let todos = [{title: "abc"}, {title: "def"}]
function addTodo(title) {
  let found = todos.find(item => item.title == title)
  if (found) {
    console.log("todo already exists")
  } else {
    todos.push({title: title})
  }
}

Use the above function when adding new items to the todo list

addTodo("abc")

Since "abc" is already present, an error will be shown in the console

addTodo("xyz")

This time, "xyz" will be added to the todo list

When it comes to iterating through arrays in nodejs

Answer №1

Answer №2

Answer №3

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