Vue defines array method

Vue.js is a very popular JavaScript framework, which is widely used in single-page application development, component writing, etc. In Vue.js, array is a commonly used data structure that can help us handle some complex data logic. Below, we will introduce the commonly used array methods in Vue.js.

1. push()

push() method can add one or more elements to the array and return the new array length. For example, define an array in Vue.js:

data(){
  return {
    colors: ['red', 'green', 'blue']
  }
}

We can use the push() method to add a new element to the array:

methods: {
  addColor() {
    this.colors.push('yellow');
  }
}

Here we define an addColor() method, Each time this method is called, a new color element ('yellow') is added to the array.

2. pop()

The pop() method can remove the last element from the array. For example, define an array in Vue.js:

data() {
  return {
    fruits: ['apple', 'banana', 'orange']
  }
}

We can use the pop() method to delete the last element in the array:

methods: {
  removeFruit() {
    this.fruits.pop();
  }
}

Here we define a removeFruit() method, Each time this method is called, the last element in the array is removed.

3. unshift()

The unshift() method can add one or more elements to the beginning of the array and return the new array length. For example, defining an array in Vue.js:

data() {
  return {
    numbers: [3, 4, 5]
  }
}

We can use the unshift() method to add a new element to the beginning of the array:

methods: {
  addNumber() {
    this.numbers.unshift(2);
  }
}

Here we define an addNumber() method, each time this method is called, a new number (2) is added to the beginning of the array.

4. shift()

The shift() method can remove an element from the beginning of the array and return the value of the element. For example, defining an array in Vue.js:

data() {
  return {
    cars: ['BMW', 'Audi', 'Mercedes']
  }
}

We can use the shift() method to delete an element from the beginning of the array:

methods: {
  removeCar() {
    this.cars.shift();
  }
}

Here we define a removeCar() method, Each time this method is called, the first element ('BMW') in the array is deleted.

5. slice()

The slice() method can return a new array containing the elements selected from the original array. For example, defining an array in Vue.js:

data() {
  return {
    animals: ['dog', 'cat', 'lion', 'tiger', 'monkey']
  }
}

We can use the slice() method to return a new array that starts from the second element of the original array (subscript 1) and ends at The fourth element (subscript 3) ends:

computed: {
  selectedAnimals() {
    return this.animals.slice(1, 4);
  }
}

Here we define a computed attribute that returns a new array containing the elements selected from the original array ('cat', ' lion' and 'tiger').

6. splice()

The splice() method can add or remove one or more elements to an array. For example, defining an array in Vue.js:

data() {
   return {
    cities: ['New York', 'London', 'Paris', 'Tokyo']
  }
}

We can use the splice() method to add a new element to the array:

methods: {
  addCity() {
    this.cities.splice(2, 0, 'Shanghai');
  }
}

Here we define an addCity() method, It first specifies that the splice() operation starts at index 2, then moves the remaining elements backward and adds a new element ('Shanghai') at index 2.

At the same time, we can also use the splice() method to delete an element in the array:

methods: {
  removeCity() {
    this.cities.splice(1, 1);
  }
}

Here we define a removeCity() method, which starts from subscript 1 and deletes an element. element('London').

Conclusion:

The above are the commonly used array methods in Vue.js. Understanding these methods can help us write Vue.js applications more efficiently. Of course, there are many other array methods, you can check the documentation yourself when needed.

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