What is the reason why WeChat Mini Programs directly prints this as undefined in the bindblur event function bound to the element?

I bound an out-of-focus event to an element, but the undefined, code for printing this directly in the out-of-focus event function is as follows:

<input id="peopleName" bindblur="VerifyName" type="text" placeholder="" placeholder-class="placeholder"></input>

VerifyName:e=>{
    console.log(this); //undefined
    const testName = /^[\u4E00-\u9FA5\uf900-\ufa2ds]{2,20}$/;
    if (testName.test(e.detail.value)) {
      console.log("");
    } else {
      console.log("");
    }
  }

Don't write as an arrow function

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1bf86ce-320d4.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1bf86ce-320d4.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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