How do I compare strings in Java?

== tests for reference equality (whether they are the same object). .equals() tests for value equality (whether they are logically “equal”). Objects.equals() checks for null before calling .equals() so you don’t have to (available as of JDK7, also available in Guava). Consequently, if you want to test whether two strings have the same value you … Read more

How do I check for null values in JavaScript?

JavaScript is very flexible with regards to checking for “null” values. I’m guessing you’re actually looking for empty strings, in which case this simpler code will work: if(!pass || !cpass || !email || !cemail || !user){ Which will check for empty strings (“”), null, undefined, false and the numbers 0 and NaN. Please note that … Read more

Why does comparing strings using either ‘==’ or ‘is’ sometimes produce a different result?

is is identity testing, == is equality testing. what happens in your code would be emulated in the interpreter like this: >>> a=”pub” >>> b = ”.join([‘p’, ‘u’, ‘b’]) >>> a == b True >>> a is b False so, no wonder they’re not the same, right? In other words: a is b is the … Read more

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