I am new to android studio and kotlin. I need to find a way to check if a string contains a char, which is, in this case, "/"
I want to form a piece of code in the following manner:
if (string input contains a character "/") = true {
<code>
}
else{
<code>
}
Please tell me how to do this, and if possible, give me the code I'll need to specify as the condition.
You can use contains, like this:
val a = "hello/"
val b = a.contains("/")
When the string has the character will return true.
Related
fun SubmitOrder(view: View) {
/* pricing of coffee */
val total = quantity * 5
val s: String = ("$$total.00")
money.text = ("Total : $s\nThank You!").toString()
//This is calling On click listener
Toast.makeText(this, "order_Submitted", Toast.LENGTH_SHORT).show()
}
In this code, I need a new line before Thank You! in money.text but I am not getting any new line I am new in android development so, am not able to point out the mistake.
Let's go thru your code line by line:
val s: String = ("$$total.00")
s is a bad variable name, as it's not descriptive at all
you don't need the (braces)
the :String here is optional. In such an obvious case i would emit it.
A $ is a sign to the kotlin compiler to include the following variable. Therefore, you can't use the $ when you mean "US-Dollar". See this post on how to escape it
While ".00" works, it's no good style. I suggest you use string formatting as described here.
can be written as val s = "\$ ${String.format("%.2f", total)}"
you should wherever possible use string resources, but thats out of the scope of this answer
money.text = ("Total : $s\nThank You!").toString()
this is correct, but unnecessary verbose:
"Total : $s\nThank You!" is already a string, so there's no need to .toString()
braces are not needed
can be written as money.text = "Total : $s\nThank You!"
I am trying to concatenate 2 String but not sure how to go about it.
this is my code:
val word = R.string.word
and i'm trying to append it with "$currentPage/5" inside the setText("$currentPage/5")
i tried to make it in this way setText("$word $currentPage/5")
and this way setText("${R.string.value} $currentPage/5")
and it did not work , it only shows me numbers not the text
try to use this:
val word = getString(R.string.word)
text_view.text = "$word $currentPage/5"
If you want to edit your value (e.g. current page) wrap it with {}
E.g.
val word = getString(R.string.word)
text_view.text = "$word ${currentPage/5}"
Remember to use proper kotlin syntax
In Kotlin, the concatenation of string can be done by **interpolation/templates**.
val a = "Its"
val b = "Kotlin!"
val c = "$a $b"
The output will be Its Kotlin!
Or we can alson do concatenate using the **+ / plus() operator**:
val a = "String"
val b = "Concatenate"
val c = a + b
val d =a.plus(b)
print(c)
The output will be: StringConcatenate
print(d)
The output will be: StringConcatenate
Or you can concatenate using the StringBuilder which is a normal way to do that.
To concatenate two string, we could do
val concatenatedWord = "${resources.getString(R.string.value)}:
${number/3}."
If R.string.value was "The result" and number was 15, value of concatenatedWord will be "The result: 5."
Or we could also concatenate using the + operator or using StringBuilder.
But if you do
textView.text = "${resources.getString(R.string.value)}: ${number/3}."
AS will warn "Do not concatenate text displayed with setText." so, in the case of setting concatenated text in textview, consider using
String.format("%s: %d.", resources.getString(R.string.value):
number/3)
As a future resource and answer why the accepted answer works:-
String Templates:-
Strings may contain template expressions, i.e. pieces of code that are evaluated and whose results are concatenated into the string.
How to implement these?
A template expression should start with a dollar sign ($) and consists of either a simple name:
when the expression is a simple variable.
val i = 10
println("i = $i") // prints "i = 10"
or else arbitrary expression in curly braces:
val s = "abc"
println("$s.length is ${s.length}") // prints "abc.length is 3"
Note :- Templates are supported both inside raw strings and inside escaped strings.
val nameOfAnimal = "fish"
val speciesClass = "is an Aquatic Vertebrate"
println(nameOfAnimal.plus(speciesClass))
println(nameOfAnimal+speciesClass)
println("$nameOfAnimal $speciesClass")
Results:
fishis an Aquatic Vertebrate
fishis an Aquatic Vertebrate
fish is an Aquatic Vertebrate
So I have the following string:
String text = "\t\t\torder #168\n\t\t\tpaid\n\t\t\tview 4 items\n\t\t\tpicked up\n\t\t\tcomplete pickup\n\t\t\t2 stops";
How do I parse this string so that I always get the 2 in front of stops? I have tried the following, but it always returns 2 stops.
String substr = "complete pickup";
String numberOfStops = text.substring(text.indexOf(substr) + substr.length());
numberOfStops = numberOfStops.replaceAll("^\\s+","").replaceAll("\\s+$","");
The short way:
numberOfStops = numberOfStops.replaceAll("^\\s+","").replaceAll("\\s+$","").replace("stops","");
The flexible way is using Regex, and Pattern and Match classes. Let me know if you need it
I'm trying to remove all text tagged like this (including the tags)
<tag>TEXT</tag>
from a String.
I have tried
.replaceAll("<tag>.+/(tag)*>", "")
or
.replaceAll("<tag>.*(tag)*>", "")
but neither works correctly and I can't replace the tagged text with ""
I don't know exactly what you want, so here are a few options:
String text = "ab<tag>xyz</tag>cd";
// Between
text.replaceAll("<tag>.+?<\/tag>", "<tag></tag>"); // ab<tag></tag>cd
// Everything
text.replaceAll("<tag>.+?<\/tag>", ""); // abcd
// Only tags
text.replaceAll("<\/?tag>", ""); // abxyzcd
EDIT:
The problem was the missing ? after the .+. The question mark only matches the first occurence, so it works when multiple tags are present which was the case.
Change to this ,
String nn1="<tag>TEXT</tag>";
nn1=nn1.replace("<tag>","");
nn1=nn1.replace("</tag>","");
OR
String nn1="<tag>TEXT</tag>";
nn1=nn1.replaceAll("<tag>","");
nn1=nn1.replaceAll("</tag>","");
Output : TEXT
I hope this helps you.
public static void removeTAG()
{
String str = "<tag>Your Long String</tag>";
for(int i=0;i<str.length();i++)
{
str = str.replace("<tag>", "");
str = str.replace("</tag>", "");
}
System.out.println(str);
}
Here what i did and output was as expected
Output Your Long String
You can use the below regular expression.
.replaceAll("<tag>.+?<\/tag>", "<tag></tag>");
This removes all the tags whether it's an HTML or an XML tag.
I am trying to add a number and a text input value to display in a label. here is my code thus far.
'lblAnswer.text = bloodglucose + 100;'
Please tell me what I am doing wrong.
Please try following answer -
bloodglucose += 100;
lblAnswer.text = String(bloodglucose);
Hope this will work :)
Sunil is correct - when doing mixed type addition, the UI input first needs to be coerced to either int or Number. IE: Number(bloodglucose) + 100; This assumes bloodglucose is actually a getter to the input text reference. If it's not, then you need to coerce the property and not the id of the component.
Getter: public function get bloodglucose():Number { return Number(myInput.text); }
In method: lblAnswer.text = bloodglucose + 100;
or (bloodglucose is a UIComponent):
In method: lblAnswer.text = Number(bloodglucose.text) + 100;
You should use String(int i)
lblAnswer.text = String(bloodglucose + 100);
Update: What about something like this:
var i:int = bloodglucose + 100;
var s:String = String(i);
lblAnswer.text = s;
** Update ,
I am changing the code from the update that was previously posted. I initially found that because I was including the string value inside of the equation this is what was prompting an error. You have to wrap the converted components to Number inside of the string all together. Basically convert the components to a number, then convert the answer received into a string.
Below is an example of the wrong code.
txtAnswer = (String(Number(bloodglucose)+100)) / 36)).toFixed(2)
Below this line is the fixed code.
txtAnswer.text = String( (Number(bloodglucose.text) + (Number(100))/ (Number(36))).toFixed(2) ;
The .toFixed Property signifies how many decimal places I want the returned value to display.