Using the Pythagorean theorem with Java

I’m trying to create this program that essentially solves the 3rd value of a right triangle. So the hypotenuse will always be 1, and one of the values (lets call it ‘x’) will be greater than or equal to -1 but less than or equal to 1. First, I created a loop to include all …

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Checking if a key exists in a JavaScript object?

Checking for undefined-ness is not an accurate way of testing whether a key exists. What if the key exists but the value is actually undefined? Expand snippet You should instead use the in operator: Expand snippet If you want to check if a key doesn’t exist, remember to use parenthesis: Expand snippet Or, if you …

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GCC: Array type has incomplete element type

It’s the array that’s causing trouble in: The second and subsequent dimensions must be given: Or you can just give a pointer to pointer: However, although they look similar, those are very different internally. If you’re using C99, you can use variably-qualified arrays. Quoting an example from the C99 standard (section § Array Declarators): Question …

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Create an empty object in JavaScript with {} or new Object()?

Objects There is no benefit to using new Object(); – whereas {}; can make your code more compact, and more readable. For defining empty objects they’re technically the same. The {} syntax is shorter, neater (less Java-ish), and allows you to instantly populate the object inline – like so: Arrays For arrays, there’s similarly almost no benefit to ever using new Array(); over []; – …

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Java says this method has a constructor name

You can’t use the class name as the name for a method. The only “methods” that can share a name with the class are constructors. One fix would be to rename your class from isPalindrome to PalindromeFinder or something. That would also better align with Java naming conventions. EDIT: Note that you never actually called your method in main; …

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Print array elements on separate lines in Bash?

Try doing this : The difference between $@ and $*: Unquoted, the results are unspecified. In Bash, both expand to separate args and then wordsplit and globbed. Quoted, “$@” expands each element as a separate argument, while “$*” expands to the args merged into one argument: “$1c$2c…” (where c is the first char of IFS). You almost always want “$@”. Same goes for “${arr[@]}”. Always quote them!

Array to Hash Ruby

That’s it. The * is called the splat operator. One caveat per @Mike Lewis (in the comments): “Be very careful with this. Ruby expands splats on the stack. If you do this with a large dataset, expect to blow out your stack.” So, for most general use cases this method is great, but use a …

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