How does vue add new fields to the array returned by the interface?

how does vue cycle through adding a new field to the array majors in res.list such as: the activeName field defaults to false.

Apr.05,2021

Vue.set


this.res.list.majors.forEach(item => {
    this.$set(item, 'activeName', false)
})
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-64f5-1e9e17f-466ef.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e9e17f-466ef.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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