All Questions

2
answers

How to create a for in R with the indexes of a data frame

If I have a data.frame: > dato<-as.data.frame(matrix(1:64,8,8,T))[-3,] > dato V1 V2 V3 V4 V5 V6 V7 V8 1 1 2 3 4 5 6 7 8 2 9 10 11 12 13 14 15 16 4 25 26 27 28 29 30 31 32 5 33 34 35 36 37 38 39 40 6 41 42 43 44 45 46 47 48...
asked on 01.05.2018 / 16:15
1
answer

How to remove Input buttons type="number"

How to remove the two buttons of Input type="number" in HTML5? Example: <p>Quero que isso:</p> <input type="number"> <p>Vire isso porém sem usar o text, pois preciso do comportamento do number:</p> <in...
asked on 04.08.2017 / 15:55
2
answers

What to do so that when the user hover over an image, it widens a bit? (preferably using only HTML and CSS)

I wanted that when the user hovered over a certain image, the image widened a little, and that's all.     
asked on 06.10.2017 / 17:57
1
answer

How does for (?;) work?

It's probably duplicated, but I did not find it here in SOpt, and I do not know how to search on Google. How does the for loop work in this syntax? for(;;) { //... }     
asked on 20.10.2017 / 18:29
1
answer

Why should not iterate a hashmap?

I've been doing a project and one of my colleagues mentioned that iterating hashmaps is something to avoid and instead should use hashmap . However, I think the hashmap's versatility of being able to save strings as a key allows you to...
asked on 10.01.2018 / 21:25
3
answers

Builder builder?

I would like to understand why this class has two constructors and why one of them has everything inside this and not separate as in the other. Does that change anything? Normal constructor: public Conta(Correntista correntista, String...
asked on 24.06.2017 / 17:36
2
answers

Does the unit of measurement "on" change in each device?

When I put the unit "1em" in a font-size for a desktop for example, it will be 15px by default already in the browser. But the "in" is worth a smaller size for a mobile device for example, right?     
asked on 20.07.2017 / 22:45
5
answers

What is the difference between comparison operators in Oracle?

In Oracle there are several operators to make comparisons of "different", such as: <> ¬= != ^= Example: Select * from tabel where nomeTabela <> 's'; Select * from tabel where nomeTabela != 's'; Select * from tabel where nomeTa...
asked on 30.10.2017 / 13:58
1
answer

Using Switch Case for Intervals

My teacher passed an exercise in which we should use the cases of a switch to handle intervals, he said strictly that we should use the switch and we can not use if nor while/do . I've tried the following code: switch(saldo)...
asked on 24.11.2017 / 18:17
1
answer

Are Java 8 lambdas and streams bringing more benefits beyond conciseness?

The only benefits I realize in the lambdas and streams of Java 8 are code savings and, as the case may be, better express the author's intent. Is that all? Is there any example code that uses one of these features and is it better not onl...
asked on 23.07.2017 / 16:32