What is custom formatting?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of Vue.js conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
You can use custom formatting for some of the formatting cases such as ICU formatting syntax (message "pattern"
strings with variable-element placeholders enclosed in {curly braces}). It implement Formatter Interface.
// Custom Formatter implementation
class CustomFormatter {
constructor (options) {
// ...
}
interpolate (message, values) {
// return the interpolated array
return ['resolved message string']
}
}
// register with `formatter` option
const i18n = new VueI18n({
locale: 'en-US',
formatter: new CustomFormatter(/* here the constructor options */),
messages: {
'en-US': {
// ...
},
// ...
}
})
// Run!
new Vue({ i18n }).$mount('#app')
****
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.