topic Re: difference between row2.state.equals('Arizona') vs 'Arizona'.equals(row2.state) in Talend Studio

difference between row2.state.equals('Arizona') vs 'Arizona'.equals(row2.state)

amtkmr1990 — Mon, 09 Sep 2019 08:35:43 GMT

Hello Team,

Could help me explain the difference between

row2.state.equals('Arizona') vs 'Arizona'.equals(row2.state)

in expresssion under tjoin inner join tab.

TRF — Mon, 09 Sep 2019 08:44:13 GMT

"Arizona".equals(row2.state) will never finish by a null pointer exception but row2.state.equals("Arizona") will fail if row2.state is null.

amtkmr1990 — Mon, 09 Sep 2019 09:49:36 GMT

thanks TRF.

rmartin2 — Mon, 09 Sep 2019 09:50:16 GMT

As TRF said, you should NEVER use the first one.

The second create a static String object, which prevent any exception, so you can do many operations like : !"".equals(row1.data)

The first syntax is a bad syntax and should be banned from all Java code you can ever find

You can use that trick in many situations if you're not sure of the nullability of your String.

Example : row1.data+"" will never be null, even if "data" is an Integer

amtkmr1990 — Mon, 09 Sep 2019 10:24:48 GMT

Actually i was using this Arizona'.equals(row2.state) in tmap to only select rows with Arizona.

TMSSQLinput - tmap - MSSQLoupt

tmssqlinput (Lookup) - above tmap