What is the best way to implement multiple conditions in v-if within VueJS?

Question

What is the best way to implement multiple conditions in v-if within VueJS?

Below is the code snippet I am working with:

JavaScript

let Names = [
    {
        Name: "Josh"
        FullName: ""
    },
    {
        Name: "Jonathan"
        FullName: null
    },
    {
        Name: "James"
        FullName: "James Johnson"
    }
];

Index.Vue

<ul>
    <li
        v-for="item in Names" 
        v-if=" item.FullName != null || item.FullName != '' "
    >
     {{FullName}}
    </li>
</ul>

The code

v-if=" item.FullName != null || item.FullName != '' "

seems to be ineffective. Can you explain why it's not working and suggest a way to include two conditions within a v-if statement?

javascript vue.js vuejs2

Answer 1

Answer №1

Perhaps the issue lies in how you are handling empty strings as false values and using || to display fullname if either expression is true, which may not be your intended behavior.

Consider trying this approach instead:

<li v-for="item in Names" v-if="item.FullName !== null && item.FullName !== ''">

Furthermore, based on your code, it seems like {{ FullName }} should actually be {{ item.FullName }}

Answer 2

Perhaps the issue lies in how you are handling empty strings as false values and using || to display fullname if either expression is true, which may not be your intended behavior.

Consider trying this approach instead:

<li v-for="item in Names" v-if="item.FullName !== null && item.FullName !== ''">

Furthermore, based on your code, it seems like {{ FullName }} should actually be {{ item.FullName }}

Answer 3

Answer №2

Jenny's response is spot on, even though this question may be a bit outdated, there are some important points to consider:

First of all, it is recommended to avoid using v-for with v-if in the same element! (source: https://v2.vuejs.org/v2/style-guide/#Avoid-v-if-with-v-for-essential)

Secondly, if you need to use v-if with || operator, it is best to utilize a computed property or a simple method.

Lastly, I believe it is preferable to use camelCase instead of PascalCase for variables and object keys.

<li v-if="checkIfFullNameExists(item)">
  <span>{{ item.fullName }}

If opting for a method:

methods: {
  checkIfFullNameExists (item) {
    if (![null, ''].includes(item.fullName)) return true
  }
}

Answer 4

Jenny's response is spot on, even though this question may be a bit outdated, there are some important points to consider:

First of all, it is recommended to avoid using v-for with v-if in the same element! (source: https://v2.vuejs.org/v2/style-guide/#Avoid-v-if-with-v-for-essential)

Secondly, if you need to use v-if with || operator, it is best to utilize a computed property or a simple method.

Lastly, I believe it is preferable to use camelCase instead of PascalCase for variables and object keys.

<li v-if="checkIfFullNameExists(item)">
  <span>{{ item.fullName }}

If opting for a method:

methods: {
  checkIfFullNameExists (item) {
    if (![null, ''].includes(item.fullName)) return true
  }
}

Answer 5

Answer №3

To optimize your code, it is recommended to utilize computed properties.

computed: {
    condition() {
      this.FullName;
      return this.FullName !== null && this.FullName !== '';
    }
  }

This computed property can be used as a condition in your code.

<li v-for="item in Names" v-if="condition>

Instead of using {{ FullName }}, make sure to use {{ item.FullName }}. The error was caused by referencing the wrong property. Additionally, consider using && instead of ||.

You can also improve your code like this:

 <li v-for="item in Names" v-if="item.FullName !== null && item.FullName !== ''>

Answer 6

To optimize your code, it is recommended to utilize computed properties.

computed: {
    condition() {
      this.FullName;
      return this.FullName !== null && this.FullName !== '';
    }
  }

This computed property can be used as a condition in your code.

<li v-for="item in Names" v-if="condition>

Instead of using {{ FullName }}, make sure to use {{ item.FullName }}. The error was caused by referencing the wrong property. Additionally, consider using && instead of ||.

You can also improve your code like this:

 <li v-for="item in Names" v-if="item.FullName !== null && item.FullName !== ''>

Answer 7

Answer №4

If you want to simplify your template and make your code more self-documenting, consider creating a computed property that evaluates all conditionals and then use a single v-if for that computed property. This approach will result in a cleaner template and easier-to-understand code.

Answer 8

If you want to simplify your template and make your code more self-documenting, consider creating a computed property that evaluates all conditionals and then use a single v-if for that computed property. This approach will result in a cleaner template and easier-to-understand code.

Answer 9

Answer №5

Straightforward and uncomplicated.

<li v-for="item in Names" v-if="!!item.FullName>

When working with Javascript, !!0 will result in false, !!1 will result in true, !!"" will result in false, !!"a" will result in true, and !!null will result in false

Answer 10

Straightforward and uncomplicated.

<li v-for="item in Names" v-if="!!item.FullName>

When working with Javascript, !!0 will result in false, !!1 will result in true, !!"" will result in false, !!"a" will result in true, and !!null will result in false

What is the best way to implement multiple conditions in v-if within VueJS?

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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