I have a vue filter and display some values. I would like to change the value when the value's last digit is between 2 and 4. I need to have an automatised code so it works for all possible intervals, for example: (22-24, 32-34, 622-624...).
I managed to find the last digit of a value: value.toString()[value.toString().length - 1]. I am not sure how to solve this problem, maybe I should come up with a special matematical formula?
myfilter: (value): => {
if(value >= 22 && value <= 24) {
return 'my new value'
}
}
You can use the modulus operator: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Remainder_()
myfilter: (value): => {
if(value % 10 <= 4 && value % 10 >= 2 ) {
return 'my new value'
}
}
Related
On the Android Studio emulator The user is required to enter a maximum of 10 numbers. When I put in the number 1 the output shows 0 instead of 1 (this is for the min number; the max works perfectly fine) Can anyone please assist me in this problem. I tried using minOf() and max() nothing worked Below is a snippet of my source code:
val arrX = Array(10) { 0 }
.
.
.
.
findMinAndMaxButton.setOnClickListener {
fun getMin(arrX: Array<Int>): Int {
var min = Int.MAX_VALUE
for (i in arrX) {
min = min.coerceAtMost(i)
}
return min
}
fun getMax(arrX: Array<Int>): Int {
var max = Int.MIN_VALUE
for (i in arrX) {
max = max.coerceAtLeast(i)
}
return max
}
output.text = "The Min is "+ getMin(arrX) + " and the Max is " + getMax(arrX)
}
}
}
Is there anything that can be done to get this work?
You're initialising arrX to a bunch of zeroes, and 0.coerceAtMost(someLargerNumber) will always stick at 0.
Without seeing how you set the user's numbers it's hard to say what you need to do - but since you said the user enters a maximum of 10 numbers, at a guess there are some gaps in your array, i.e. indices that are still set to 0. If so, they're going to be counted in your min calculation.
You should probably use null as your default value instead - that way you can just ignore those in your calculations:
val items = arrayOfNulls<Int?>(10)
// this results in null, because there are no values - handle that however you like
println(items.filterNotNull().minOrNull())
>> null
// set values on some of the indices
(3..5).forEach { items[it] = it }
// now this prints 3, because that's the smallest of the numbers that -do- exist
println(items.filterNotNull().minOrNull())
>> 3
Ex 10.0 = 10
10.3 = 10.3
10.7 = 10. 7
Looking for a convenient way from Kotlin Standard library
You can use the following function:
fun removeTrailingZeros(num: String): String {
if(!num.contains('.')) // Return the original number if it doesn't contain decimal
return num
return num
.dropLastWhile { it == '0' } // Remove trailing zero
.dropLastWhile { it == '.' } // Remove decimal in case it's the last character in the resultant string
}
You can verify the code here
You can try this:
double number = 23.471;
if (number % 1 != 0)
{
//round off here
System.out.print ("Decimal");
}
else
{
System.out.print ("Integer");
}
If you want to get a string, the easiest way is to work with a string like num.toString().replace(".0",""). For numbers conversion does not make sense since the resulting type is different for different inputs.
I have tried many thing involving this, >=, >==, =>, ==>.i can not find one that works. hey all return either primary expression needed or expected initializer before '>'. I am creating a IR receiver latch switch and thus have to create parameters for the code because the receiver is not constant in all conditions. Full code below. Any suggestions to fix the code please reply and don't DM me. Thank you.
code:
int LEDState = 0;
int LEDPin = 8;
int dt = 100;
int recieverOld ==> 500 and recieverOld ==< 2000;
int recieverNew;
int recieverPin = 12;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(LEDPin, OUTPUT);
pinMode(recieverPin, INPUT);
}
void loop() {
// put your main code here, to run repeatedly:
recieverNew = digitalRead(recieverPin);
if((recieverOld >== 0 && recieverOld <== 10) && (recieverNew >== 500 && recieverNew <== 2000) {
if(LEDState == 0) {
digitalWrite(LEDPin, HIGH);
LEDState = 1;
}
}
recieverOld = recieverNew;
delay(dt);
}
error:
expected initializer before '==' token
if one = used line 4 and related, return error expected primary-expression before '>' token
if > before = line 4 and related, return error expected initializer before '>=' token
Any solutions or suggestions welcome.
TL;DR
Operators that do no exist, and that you should NOT use:
==>, ==<, >==, <==
Operators that works and you can use them:
>= - MORE THAN OR EQUAL, compare operator, for example X >= 5
<= - LESS THAN OR EQUAL, compare operator, for example X <= 5
> - MORE THAN, compare operator, for example X > 5
< - LESS THAN, compare operator, for example X < 5
== - compare operator, when you want to compare values of the variables if they have the same value, for example X == 5, Y == X, 10 == 7
=== - equality operator, similar to compare operator ==, but aditionally checks the type of a variable. for example X === Y, '10' === 10
= - assign operator, when you want to assign something to the variable, for example X = 5
<> OR != - NOT EQUAL, compare operator, for example X != 5, Y <> 10
!== - similar to != or <>, but also checks the type of a value. For example 10 !== '10', and will return opposite result of the equality operator ===
val listNumbers = generateSequence(1) { it + 1 }
val listNumber1to100 = listNumbers.takeWhile { it < 100 }
val secNum:Unit = listNumber1to100.forEach {it}
println(listNumber1to100.asSequence().filter { it%(listNumber1to100.forEach { it })!=0 }.toList())
I have an error in reminder sign!
This is Error: None of the following functions can be called with the arguments supplied
In your first approach, the error appears in this line:
it%(listNumber1to100.forEach { it })
A Byte, Double, Float, Int, Long or Short is prefered right after the % operator, however, forEach is a function which the return type is Unit.
In your second approach, you have the correct expression in isPrime(Int). Here are some suggestions for you:
listNumber1to100 is excluding 100 in your code, if you want to include 100 in listNumber1to100, the lambda you pass to takeWhile should be changed like this:
val listNumber1to100 = listNumbers.takeWhile { it <= 100 }
listNumber1to100.asSequence() is redundant here since listNumber1too100 is itself a TakeWhileSequence which implements Sequence.
isPrime(Int) is a bit confusing since it is check for isComposite and it does not work for every input it takes(it works for 1 to 99 only). I will rewrite it in this way:
fun isPrime(num: Int): Boolean = if (num <= 1) false else !(2..num/2).any { num % it == 0 }
Since prime number must be positive and 1 is a special case(neither a prime nor composite number), it just return false if the input is smaller or equal to 1. If not, it checks if the input is divisible by a range of number from 2 to (input/2). The range ends before (input/2) is because if it is true for num % (num/2) == 0, it is also true for num % 2 == 0, vise versa. Finally, I add a ! operator before that because a prime number should not be divisible by any of those numbers.
Finally, you can filter a list by isPrime(Int) like this:
println(listNumber1to100.filter(::isPrime).toList())
PS. It is just for reference and there must be a better implementation than this.
To answer your question about it, it represents the only lambda parameter inside a lambda expression. It is always used for function literal which has only one parameter.
The error is because the expression: listNumber1to100.forEach { it } - is not a number, it is a Unit (ref).
The compiler try to match the modulo operator to the given function signatures, e.g.: mod(Byte) / mod(Int) / mod(Long) - etc.
val listNumbers = generateSequence(1) { it + 1 }
val listNumber1to100 = listNumbers.takeWhile { it < 100 }
fun isPrime(num: Int): Boolean = listNumber1to100.asSequence().any { num%it==0 && it!=num && it!=1 }
println(listNumber1to100.asSequence().filter { !isPrime(it)}.toList())
I found this solution and worked
But why can I have a non-number here in the right side of reminder
For generating the bingo ticket generator I need the shuffling array .
When I press a button I should retrive the values from array (ex. array(1,2,3,4,5,6,7,8,9)). I
If I retrive first five random value may be 2 5 7 4 8. If press the button again then it should retrive other than previously retrived value (ex. 1 3 9 6 7)
I don't know if you are allowed to modify your input but why not try something like this :
// passing your array as argument
// passing the total number you want to extract as argument
function getRandNumbers( a:Array, requested_numbers:Number ):Array
{
// verify we don't request to much numbers
if ( requested_numbers > a.length )
{
trace( "Not enought available numbers in array" );
return null;
}
results_array = new Array(); // create our output array
while( results_array.length < requested_numbers )
{
rnd = Math.floor( Math.random() * a.length );
results_array.push( a[rnd] );
a.splice( rnd, 1 ); // remove the random result
}
}
now you're sure your array will contain only non used numbers each time you will call getRandNumbers.