In [undefined,undefined] .map (Number.call, Number), what do the last two parameters mean?

Why the return value is [0pm 1pm 2pm 3pm.] What about this format?

Jul.19,2021

Array.prototype.map takes the first argument to the callback function, and the second argument to the callback function's th value.

so the original code is equivalent to

[undefined, undefined].map((element, index) => Number.call(Number, index))

that is, each element is Number (index)

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-64f5-1e3e2b4-447b0.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e3e2b4-447b0.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?