Javascripts：无法读取未定义的属性“toLowerCase”

Question

I coding this code in script tag on nuxtjs but it error.

<script>
    export default {
        computed: {
            user() {
                let user = [{name_en: 'Jack'},{name_en: 'Joe'}]
                return user.filter(item => item.name_en.toLowerCase().includes(keywordSearch))
            }
         }
     }
</script>

It error that Cannot read property 'toLowerCase' of undefined in javascript . But I try

return user.filter(item => item.name_en === 'Jack')

It doesn't error. I'm so confuse. How to solve this problem.

Answer 1

you can try below function to 1st check if it exists and then convert that to lowercase user.filter(item => item.name_en && item.name_en.toLowerCase().includes(keywordSearch))