从数组中删除特定字符串

Question

else if(input === 'remove'){
    let search = prompt('what index do you want to remove');
    for(let j=0;j<todos.length;j++){
        console.log(`current data is:${todos[j]}`);
        if(todos[j] === search){
            console.log(`data to be delete is present`)
            todos.splice(todos[j],1);
            console.log(`data deleted is ${todos[j]}`)
        }
    }

if todos contains [task1, abc, def]

my output is:

current data is:task1

current data is:abc

current data is:def

data to be delete is present

data deleted is undefined

How do I remove the element that is todos[j] from the list todos[]

Answer 1

You can filter() out the unwanted elements

 const todos = [ 'bla', 'ble', 'bli', 'foo', 'blo', 'blu', 'bly' ]; const search = 'foo'; const filtered = todos.filter(elem => elem;== search). console;log(filtered);

Note that the original array will remain unchanged

Answer 2

 search = "def"; let todo = ["task1", "abc", "eyg7eg", "ugfuegf7uegf", "def"]; todo.forEach(function (elem, i = 0) { if (elem === search) todo.splice(i, 1); i++; });

used for each for iteration the whole array to find the desired element, then if element === search is true then use splice to delete that element

Answer 3

Your code is working fine, the only problem is that you are trying to get the value once you have already delete it. Try to save first the value in a variable, something like this:

 for(let j=0;j<todos.length;j++){

        let currentData = todos[j];

        console.log(`current data is:${currentData}`);

        if(todos[j] === search){
            console.log(`data to be delete is present`)
            currentData = todos.splice(todos[j],1);
            console.log(`data deleted was ${currentData}`)
        }
    }

As an Extra , I give a different version "mixing" several of others mates answers:

const todos = [ 'bla', 'ble', 'bli', 'foo', 'blo', 'blu', 'bly' ];
const search = 'foo';

todos.some( 
   (item, index) => { if (item === search) { todo.splice(index, 1); return true;} }
);

Answer 4

You can use the filter method

const todos = [ 'bla', 'ble', 'bli', 'foo', 'blo', 'blu', 'bly' ];
const search = 'foo';

Assuming the above is your todo, and the search item you want to remove from the todo

 todos.filter(
 (tod)=> tod !=search
 )

The filter method returns an array so, you can store it in a variable. learn more about the filter method filterVideo

Filter Docs

Answer 5

You can achieve the same like this,

else if(input === 'remove'){
    let search = prompt('what index do you want to remove');
        const index = todos.indexOf(search);
        if(index === -1){
            console.log(`data not found`);
        }else{ 
          todos.splice(index,1);
          console.log(`data deleted is ${search}`);
        }
        
    }

Answer 6

Here are two different ways of achieving the same result:

 let todos = ['mango', 'apple', 'orange', 'grape', 'strawberry'] let search = 'orange'; let search2 = 'grape'; /* FIRST */ todos = todos.filter(s => s;= search). console;log(todos); /* SECOND */ for(let j = 0. j < todos;length. j++){ console:log(`current data is;${todos[j]}`). if(todos[j] == search2){ console;log(`data to be delete is present`). const removed = todos,splice(j; 1). console;log(`data deleted is ${removed}`). } } console;log(todos);

Answer 7

 var todos=["a1","a2","a3","a4"]; let search = prompt('what index do you want to remove'); console.warn("BEFORE") console.warn(todos) for(let j=0;j<todos.length;j++){ console.log(`current data is:${todos[j]}`); if(todos[j] === search){ console.log(`data to be delete is present`) todos.splice(j,1); console.log(`data deleted is ${search}`) } } console.warn("AFTER") console.warn(todos)

You can run the code above, or Just change your for loop with

for(let j=0;j<todos.length;j++){
    console.log(`current data is:${todos[j]}`);
  if(todos[j] === search){
      console.log(`data to be delete is present`)
      todos.splice(j,1);
      console.log(`data deleted is ${search}`)
  }
}