From: Felix Windt Date: 2007-08-30T07:50:35+09:00 Subject: Re: Adding elements of one array to another ------=_NextPart_000_0042_01C7EA53.C4D88DA0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit > -----Original Message----- > From: Todd Benson [mailto:caduceass@gmail.com] > Sent: Wednesday, August 29, 2007 3:38 PM > To: ruby-talk ML > Subject: Re: Adding elements of one array to another > > On 8/29/07, Ari Brown wrote: > > I can't remember who asked this a while ago, but while I was > > stumbling through my Programming Ruby book, I found a nice > method in > > array that will instantly do the trick: Array#concat > > > > > > a = [1, 2] > > b = [3, 4] > > a.concat(b) #=> [1, 2, 3, 4] > > There's also a+=b. I'm not sure if there's a difference. > > Todd > There's a considerable performance difference: $ cat test.rb require 'benchmark' n = 50_000 Benchmark.bm do |x| a = [1,2] b = [3,4] x.report { n.times { a += b } } x.report { n.times { a.concat b } } end $ ruby test.rb user system total real 5.370000 1.260000 6.630000 ( 6.664451) 0.030000 0.020000 0.050000 ( 0.051235) As concat acts directly on self, whereas + creates a third object. HTH, Felix ------=_NextPart_000_0042_01C7EA53.C4D88DA0 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIII3jCCAmYw ggHPoAMCAQICEFJ3uelO4AJUNG7Np2ieTWkwDQYJKoZIhvcNAQEFBQAwYjELMAkGA1UEBhMCWkEx JTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQ ZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBMB4XDTA3MDMxMTEzMzk1OVoXDTA4MDMxMDEzMzk1 OVowSjEfMB0GA1UEAxMWVGhhd3RlIEZyZWVtYWlsIE1lbWJlcjEnMCUGCSqGSIb3DQEJARYYZndt YWlsaW5nbGlzdHNAZ21haWwuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDoHQNMSMIi 1fb3BhJdz7Byt8PSeaa/Yx0wJ1BzLj7dJZK+8djBP06HvolZ9IYibnGerNg+LnxXT8tyGUZ0vw0Q f3qSYtuGcYfdm44qVOAtV+fex14uBSmSj8i/QOL+710oSQdPGAJE1L+8N1bLvJAxznsF6tpD5GUZ iPRY1HcloQIDAQABozUwMzAjBgNVHREEHDAagRhmd21haWxpbmdsaXN0c0BnbWFpbC5jb20wDAYD VR0TAQH/BAIwADANBgkqhkiG9w0BAQUFAAOBgQCtXsHSAFBpcohm7/t5Vlak0eySI5c5cghVELhu LyoNMdx+qCyKE4HJoWrr2+id/+YVPfiOaBsxsir3Aeg3DPuCODoafFYErm3OzJV13lRlwKWfrz01 vczScC2VvABk0ZvlQEHA54IJqiV8QoXntlQWaa2NYO3ggalUyaOeNmsk1TCCAy0wggKWoAMCAQIC AQAwDQYJKoZIhvcNAQEEBQAwgdExCzAJBgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUx EjAQBgNVBAcTCUNhcGUgVG93bjEaMBgGA1UEChMRVGhhd3RlIENvbnN1bHRpbmcxKDAmBgNVBAsT H0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJzb25h bCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3RlLmNv bTAeFw05NjAxMDEwMDAwMDBaFw0yMDEyMzEyMzU5NTlaMIHRMQswCQYDVQQGEwJaQTEVMBMGA1UE CBMMV2VzdGVybiBDYXBlMRIwEAYDVQQHEwlDYXBlIFRvd24xGjAYBgNVBAoTEVRoYXd0ZSBDb25z dWx0aW5nMSgwJgYDVQQLEx9DZXJ0aWZpY2F0aW9uIFNlcnZpY2VzIERpdmlzaW9uMSQwIgYDVQQD ExtUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgQ0ExKzApBgkqhkiG9w0BCQEWHHBlcnNvbmFsLWZy ZWVtYWlsQHRoYXd0ZS5jb20wgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBANRp19SwlGRbcelH 2AxRtupykbCEXn0tDY97Et+FJXUodDpCLGMnn5V7S+9+GYcdhuqj3bnOlmQawhRuRKx85o/oTQ9x H0A4pgCjh3j2+ZSGXq3qwF5269kUo11uenwMpUtVfwYZKX+emibVars4JAhqmMex2qOYkf152+Va xBy5AgMBAAGjEzARMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEEBQADgYEAx+ySfk749Zal Z2IqpPBNEWDQb41gWGGsJrtSNVwIzzD7qEqWih9iQiOMFw/0umScF6xHKd+dmF7SbGBxXKKs3Hnj 524ARx+1DSjoAp3kmv0T9KbZfLH43F8jJgmRgHPQFBveQ6mDJfLmnC8Vyv6mq4oHdYsM3VGEa+T4 0c53ooEwggM/MIICqKADAgECAgENMA0GCSqGSIb3DQEBBQUAMIHRMQswCQYDVQQGEwJaQTEVMBMG A1UECBMMV2VzdGVybiBDYXBlMRIwEAYDVQQHEwlDYXBlIFRvd24xGjAYBgNVBAoTEVRoYXd0ZSBD b25zdWx0aW5nMSgwJgYDVQQLEx9DZXJ0aWZpY2F0aW9uIFNlcnZpY2VzIERpdmlzaW9uMSQwIgYD VQQDExtUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgQ0ExKzApBgkqhkiG9w0BCQEWHHBlcnNvbmFs LWZyZWVtYWlsQHRoYXd0ZS5jb20wHhcNMDMwNzE3MDAwMDAwWhcNMTMwNzE2MjM1OTU5WjBiMQsw CQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UE AxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0EwgZ8wDQYJKoZIhvcNAQEBBQAD gY0AMIGJAoGBAMSmPFVzVftOucqZWh5owHUEcJ3f6f+jHuy9zfVb8hp2vX8MOmHyv1HOAdTlUAow 1wJjWiyJFXCO3cnwK4Vaqj9xVsuvPAsH5/EfkTYkKhPPK9Xzgnc9A74r/rsYPge/QIACZNenpruf ZdHFKlSFD0gEf6e20TxhBEAeZBlyYLf7AgMBAAGjgZQwgZEwEgYDVR0TAQH/BAgwBgEB/wIBADBD BgNVHR8EPDA6MDigNqA0hjJodHRwOi8vY3JsLnRoYXd0ZS5jb20vVGhhd3RlUGVyc29uYWxGcmVl bWFpbENBLmNybDALBgNVHQ8EBAMCAQYwKQYDVR0RBCIwIKQeMBwxGjAYBgNVBAMTEVByaXZhdGVM YWJlbDItMTM4MA0GCSqGSIb3DQEBBQUAA4GBAEiM0VCD6gsuzA2jZqxnD3+vrL7CF6FDlpSdf0wh uPg2H6otnzYvwPQcUCCTcDz9reFhYsPZOhl+hLGZGwDFGguCdJ4lUJRix9sncVcljd2pnDmOjCBP ZV+V2vf3h9bGCE6u9uo05RAaWzVNd+NWIXiC3CEZNd4ksdMdRv9dX2VPMYIC+DCCAvQCAQEwdjBi MQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoG A1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0ECEFJ3uelO4AJUNG7Np2ie TWkwCQYFKw4DAhoFAKCCAdgwGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUx DxcNMDcwODI5MjI0NjMwWjAjBgkqhkiG9w0BCQQxFgQUJs/SPZ7hBgbKkj8DnQI8tFwHCdkwZwYJ KoZIhvcNAQkPMVowWDAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAw BwYFKw4DAgcwDQYIKoZIhvcNAwICASgwBwYFKw4DAhowCgYIKoZIhvcNAgUwgYUGCSsGAQQBgjcQ BDF4MHYwYjELMAkGA1UEBhMCWkExJTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0 ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBAhBSd7npTuAC VDRuzadonk1pMIGHBgsqhkiG9w0BCRACCzF4oHYwYjELMAkGA1UEBhMCWkExJTAjBgNVBAoTHFRo YXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQZXJzb25hbCBGcmVl bWFpbCBJc3N1aW5nIENBAhBSd7npTuACVDRuzadonk1pMA0GCSqGSIb3DQEBAQUABIGA5oqwYvUA Axty7cr3+CDBTrq/tfR8A+5uEtvmvvYYeRvWDfuC/meW9bxcd1y5fwJFNnCzIEwHNzqjxXkPH8U0 UvDmgW0IJBjCSq7h9YeMZ5/Ap5lmryTX6pRlROIichLUwlIsCOzx6xuQ8Ro9+i36r+vTNYMTHoBn 0Z+Yap0npT8AAAAAAAA= ------=_NextPart_000_0042_01C7EA53.C4D88DA0--