How to Pass Parameters in Computed Properties in Vue.js

Introduction:

If you wonder whether it is possible to pass parameter in computed properties in Vue.js or not, you should read this tutorial.

In Vue.js, computed properties are used to dynamically calculate and return a value based on the data in the Vue instance. Computed properties can also accept parameters to further customize the calculation. Here's how you can pass parameters in computed properties in Vue.js:

Define a computed property:

First, define a computed property in your Vue instance using the computed property. You can give it a name and specify a function that will be used to calculate the value of the computed property. For example:

new Vue({
  data: {
    radius: 5
  },
  computed: {
    circleArea: function() {
      // calculate circle area based on radius
      return Math.PI * this.radius * this.radius;
    }
  }
})

In this example, a computed property called circleArea is defined, which calculates the area of a circle based on the value of radius in the data object.

Pass parameters to the computed property:

To pass parameters to the computed property, you can define the parameters as arguments in the function used to calculate the computed property value. For example, you can modify the above example to accept a radiusMultiplier parameter:

new Vue({
  data: {
    radius: 5
  },
  computed: {
    circleArea: function() {
      // calculate circle area based on radius and radiusMultiplier
      return Math.PI * this.radius * this.radius * this.radiusMultiplier;
    }
  }
})

In this updated example, the circleArea computed property accepts a radiusMultiplier parameter, which is used in the calculation of the circle area.

Use the computed property with parameters:

To use the computed property with parameters, you can simply access it like any other computed property in your Vue instance, and pass the parameters as arguments. For example:

<template>
  <div>
    <p>Circle area with radius 5: {{ circleArea }}</p>
    <p>Circle area with radius 5 and multiplier 2: {{ circleAreaWithMultiplier(2) }}</p>
  </div>
</template>

<script>
export default {
  computed: {
    circleArea: function() {
      // calculate circle area based on radius
      return Math.PI * this.radius * this.radius;
    }
  },
  methods: {
    circleAreaWithMultiplier: function(multiplier) {
      // calculate circle area based on radius and multiplier
      return Math.PI * this.radius * this.radius * multiplier;
    }
  }
}
</script>

In this example, the circleArea computed property is used without any parameters, while the circleAreaWithMultiplier computed property is used with a multiplier parameter passed as an argument.

Conclusion:

By following these steps, you can pass parameters in computed properties in Vue.js and dynamically calculate and update the computed property value based on the parameters passed. Remember that computed properties are cached and only re-calculated when the dependent data changes, so they are efficient for performance optimization in Vue.js applications.