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  • .sort strange behavior

.sort strange behavior

# Cyril Auburtin (7 years ago)
[0,1,3,4,7,8,8,9,13,17,22,23,26].concat([16,19,21,22,25,32]).sort((a,b)=>a-b)
// [ 0, 1, 3, 4, 7, 8, 8, 9, 13, 16, 17, 19, 21, 22, 22, 23, 25, 26, 32 ]

[0,1,3,4,7,8,8,9,13,17,22,23,26].concat([16,19,21,22,25,32]).sort()
// [ 0, 1, 13, 16, 17, 19, 21, 22, 22, 23, 25, 26, 3, 32, 4, 7, 8, 8, 9 ]

In the second case, it produces a weirdly sorted array, on node 8, chrome or firefox

What could explain this?

# Damian Senn (7 years ago)

Array#sort does string comparisons by default: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

# Cyril Auburtin (7 years ago)

Oh thanks right, alphabetical order by default so

2017-10-21 15:00 GMT+02:00 Damian Senn <damian.senn at gmail.com>:

# Mark Volkmann (7 years ago)

By default sort converts the values to strings and compares there Unicode values. For example, 10 would come before 3. In the first example you are overriding the default sort comparison in a way that is correct for numbers.

R. Mark Volkmann Object Computing, Inc.