# Introduction In this challenge, we will be fixing bug in the vue-router v3.4.0 version of the code where undefined values in the router query now become undefined strings. To fix this, you'll need to be proficient in the basic syntax of JavaScript. You will need to navigate to the vue-router-3.4.0 directory, locate the resolveQuery function in vue-router-3.4.0/src/util/query.js, and fix the issue based on the provided issue reproduction.
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