Efficient data processing case with computed attribute

summary:

This article will introduce the characteristics, functions and their applications in actual projects, so as to help readers better understand the importance of computed attributes and improve the efficiency of front-end development.

introduction:

In development, the computed property is an efficient way of processing data, which allows developers to calculate and return a value. This article will take you into the deep understanding of the usage and configuration methods of computed attributes.

1. Introduction to computed properties

The computed attribute is a data calculation method. It allows developers to define a computed attribute and return the calculated value when needed. The computed attribute has the following characteristics:

• Efficient data processing: The computed attribute is implemented based on a responsive system, which will automatically recalculate when the dependent data changes.
• Concise syntax: The computed attribute uses concise syntax to make the code more concise and easy to read.
• Cache calculation results: The computed attribute caches the calculation results. When the dependent data does not change, it will not be recalculated, thereby improving performance.

2. How to use the computed attribute

To use the computed property in,First, you need to define the dependent data in the component's data object, and then define the calculation method in the computed property.。
Example:

export default {
  data() {
    return {
      value1: 1,
      value2: 2
    };
  },
  computed: {
    sum() {
      return this.value1 + this.value2;
    }
  }
};

3. Application scenarios of computered attributes

The computed attribute has a wide range of applications in actual projects. The following are some typical application scenarios:

• Compute attributes and data binding: Use computed attributes to calculate and return a value and bind it to a template.
• Data filtering and processing: Use computed attribute to filter and process data to meet business needs.
• Event handling and interaction: Use the computed property to calculate and return a value and bind it to the event handling function.

4. Practical application cases

Computing properties is a very useful feature in it, which allows you to dynamically calculate new values ​​based on other responsive dependencies. Here are some practical application cases:

• Filter list: Suppose you have a user list and you want to filter based on user activity status.

<template>
  <div>
    <ul>
      <li v-for="user in activeUsers" :key="">{{  }}</li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      users: [
        { id: 1, name: 'John', active: true },
        { id: 2, name: 'Jane', active: false },
        { id: 3, name: 'Doe', active: true },
      ],
    };
  },
  computed: {
    activeUsers() {
      return (user => );
    },
  },
};
</script>

• Dynamic Computation Properties: Suppose you have a form where the user can enter numbers and you want to dynamically calculate other values ​​based on the entered numbers.

<template>
  <div>
    <input type="number" v-model="number" />
    <p>square: {{ square }}</p>
    <p>cube: {{ cube }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      number: 0,
    };
  },
  computed: {
    square() {
      return  * ;
    },
    cube() {
      return  *  * ;
    },
  },
};
</script>

• Cache computed properties: Sometimes computed properties can become very complex and you may want to cache their results without changing the dependencies. Allows you to achieve this by setting the computed property as a cached version of the responsive dependencies.

<template>
  <div>
    <p>{{ expensiveOperation }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      value: 0,
    };
  },
  computed: {
    expensiveOperation: {
      get() {
        // Here can be a complex calculation, which will not be recalculated every time it changes        return  * 2;
      },
      set(value) {
         = value;
      },
    },
  },
};
</script>

In short, computing properties are a very powerful tool that can help you manage and present your data more efficiently.

Summarize:

The computed property is an efficient way of processing data, which allows developers to calculate and return a value. Mastering the use of computed attributes can provide strong support for front-end development and improve development efficiency.

References:

• Official Documentation:/

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