I have a question about a string containing parentheses. Let me suppose that a string variable cityname is #"Boston (Massachusetts). I wonder why Xcode doesn't recognize the string inside parentheses? In the following code, only the first case is true.
// cityname = #"Boston (Massachusetts)"
if ([cityname rangeOfString:#"Boston"].location==!NSNotFound){
// true
}
if ([cityname rangeOfString:#"Massachusetts"].location==!NSNotFound){
// false
}
if (cityname isEqualToString:#"Boston (Massachusetts)"){
}
How can I make it so that I can validate the entire string even with parentheses (and apostrophes, too?)?
Thank you,
Tom
This has nothing to do with parentheses. You want [cityname rangeOfString:#"Massachusetts"].location != NSNotFound, not [cityname rangeOfString:#"Massachusetts"].location == !NSNotFound. They do totally different things.
Related
I have a reference string on which the allowed characters are listed. Then I also have input strings, from which not allowed characters should be replaced with a fixed character, in this example "0".
I can use filter but it removes the characters altogether, does not offer a replacement. Please note that it is not about being alphanumerical, there are ALLOWED non-alphanumerical characters and there are not allowed alphanumerical characters, referenceStr happens to be arbitrary.
var referenceStr = "abcdefg"
var inputStr = "abcqwyzt"
inputStr = inputStr.filter{it in referenceStr}
This yields:
"abc"
But I need:
"abc00000"
I also considered replace but it looks more like when you have a complete reference list of characters that are NOT allowed. My case is the other way around.
Given:
val referenceStr = "abcd][efg"
val replacementChar = '0'
val inputStr = "abcqwyzt[]"
You can do this with a regex [^<referenceStr>], where <referenceStr> should be replaced with referenceStr:
val result = inputStr.replace("[^${Regex.escape(referenceStr)}]".toRegex(), replacementChar.toString())
println(result)
Note that Regex.escape is used to make sure that the characters in referenceStr are all interpreted literally.
Alternatively, use map:
val result = inputStr.map {
if (it !in referenceStr) replacementChar else it
}.joinToString(separator = "")
In the lambda decide whether the current char "it" should be transformed to replacementChar, or itself. map creates a List<Char>, so you need to use joinToString to make the result a String again.
I'm just learning while doing ramda.js. Well, there are many ways to reach a goal with ramda, but there is on thing I do not understand.
I would like to check the input for an array of strings that all match one regular expression. I thought I could do it R.all(R.both(isString, isRegExp)), but it seems to deliver a true when the input is a number.
As expected R.allPass([isString, isRegExp]) gives a false with a number input.
But can anyone please explain me why R.all is returning a true? Or what and where is mistake (in thinking)?
Complete code:
var isString = R.is(String),
isMyRegExp = R.test(/^[a-z]+$/),
isMyRegExpString = R.both(isString, isMyRegExp),
isArrayOfMyRegExpStrings = R.all(isMyRegExpString),
isArrayOfMyRegExpStringsPass = R.allPass([isString, isMyRegExp]),
result = {
'all': isArrayOfMyRegExpStrings(9),
'allPass': isArrayOfMyRegExpStringsPass(9)
};
console.log(result);
// {
// all: true,
// allPass: false
// }
https://codepen.io/Eisenhardt/pen/PKLZqj
PS:
I know that I could shorten conditions with just the regexp, but there could be other situations where I need both conditions to be true. eg. isArrayOfNumber and sumOfNumbersOver50.
The second argument to R.all is expecting a list of values to test. Due to the way the function is implemented it is treating the 9 in your example as an empty list, resulting in a vacuous truth and evaluating to true.
Thanks again for the help.
I have a simple action that checks the stringValue of a textField, and if it matches - a status message prints in a second textField:
if
(textField.stringValue == (#"Whatever" )){
[outputDisplay setStringValue:#"Success"];
My question is how do I implement multiple input stringValue options in this method? For example "Whatever" "Whatever1, Whatever2" all return "Success" in the outputDisplay.
thanks.
Paul
Create a set of answers you're looking for and test if the string in question is in there.
NSSet *successStrings = [NSSet setWithObjects:#"Whatever1",
#"Whatever2",
#"Whatever3",
nil];
if ([successStrings containsObject:st]) {
[outputDisplay setStringValue:#"Success"];
}
(An array would also work, but a set is specialized for testing membership, so it's a better fit for what we're doing here.)
Firstly, to check for equality of NSString-s you should use -isEqualToString:. == compares the pointer values which often returns NO even if the two strings' contents are the same.
To check if the text field match multiple strings, you connect them with the || (or) operator, so you get
NSString* st = textField.stringValue;
if ([st isEqualToString:#"Whatever"] || [st isEqualToString:#"Whatever1"] || [st isEqualToString:#"Whatever2"]) {
[outputDisplay setStringValue:#"Success"];
I got this parameter:
$objDbCmd.Parameters.Add("#telephone", [System.Data.SqlDbType]::VarChar, 18) | Out-Null;
$objDbCmd.Parameters["#telephone"].Value = $objUser.Telephone;
Where the string $objUser.Telephone can be empty. If it's empty, how can I convert it to [DBNull]::Value?
I tried:
if ([string]:IsNullOrEmpty($objUser.Telephone)) { $objUser.Telephone = [DBNull]::Value };
But that gives me the error:
Exception calling "ExecuteNonQuery" with "0" argument(s): "Failed to convert parameter value from a ResultPropertyValueCollection to a String."
And if I convert it to a string, it inserts an empty string "", and not DBNull.
How can this be accomplished?
Thanks.
In PowerShell, you can treat null/empty strings as a boolean.
$x = $null
if ($x) { 'this wont print' }
$x = ""
if ($x) { 'this wont print' }
$x = "blah"
if ($x) { 'this will' }
So.... having said that you can do:
$Parameter.Value = $(if ($x) { $x } else { [DBNull]::Value })
But I'd much rather wrap this up in a function like:
function CatchNull([String]$x) {
if ($x) { $x } else { [DBNull]::Value }
}
I don't know about powershell, but in C# I would do something like this:
if ([string]::IsNullOrEmpty($objUser.Telephone))
{
$objDbCmd.Parameters["#telephone"].Value = [DBNull]::Value;
}
else
{
$objDbCmd.Parameters["#telephone"].Value = $objUser.Telephone;
}
Always append +"" at the end of db values...
$command.Parameters["#EmployeeType"].Value= $ADResult.EmployeeType + ""
Many years later, let me clarify:
Josh's answer shows a helpful simplification for testing strings for emptiness (relying on PowerShell's implicit to-Boolean conversion[1]), but it is unrelated to Tommy's (the OP's) problem.
Instead, the error message
"Failed to convert parameter value from a ResultPropertyValueCollection to a String."
implies that it is the non-null case that caused the problem, because $objDbCmd.Parameters["#telephone"].Value expects either a string value or [DBNull]::Value, whereas $objUser.Telephone is of type [ResultPropertyValueCollection], i.e. a collection of values.
Thus, in the non-null case, a string value must be assigned, which must be derived from the collection; one option is to take the first collection element's value, another would be to join all values with a separator to form a single string, using, e.g., [string]::Join(';', $objUser.Telephone) or, if joining the elements with spaces is acceptable (not a good idea with multiple phone numbers), simply with "$($objUser.Telephone)".[2]
Detecting an empty collection via [string]:IsNullOrEmpty() actually worked, despite the type mismatch, due to how PowerShell implicitly stringifies collections when passing a value to a [string] typed method parameter.[2]
Similarly, using implicit to-Boolean conversion works as expected with collections too: an empty collection evaluates to $false, a non-empty one to $true (as long as there are either at least two elements or the only element by itself would be considered $true[1])
Therefore, one solution is to use the first telephone number entry:
$objDbCmd.Parameters["#telephone"].Value = if ($objUser.Telephone) {
$objUser.Telephone[0].ToString() # use first entry
} else {
[DBNull]::Value
}
Note: If $objUser.Telephone[0] directly returns a [string], you can omit the .ToString() call.
In PowerShell v7+ you can alternatively shorten the statement via a ternary conditional:
$objDbCmd.Parameters["#telephone"].Value =
$objUser.Telephone ? $objUser.Telephone[0].ToString() : [DBNull]::Value
[1] For a comprehensive summary of PowerShell's automatic to-Boolean conversions, see the bottom section of this answer.
[2] When implicitly converting a collection to a string, PowerShell joins the stringified elements of a collection with a single space as the separator by default; you can override the separator with the automatic $OFS variable, but that is rarely done in practice; e.g., array 'foo', 'bar' is converted to 'foo bar'; note that this conversion does not apply when you call the collection's .ToString() method explicitly, but it does apply inside expandable (interpolating) strings, e.g., "$array".
I need to filter out characters like /?-^%{}[];$=*`#|&#'\"<>()+,\. I need replace this with empty string if it is there in the query string. Please help me out. I am using this in ASP pages.
Best idea would be to use a function something along the lines of:
Public Function MakeSQLSafe(ByVal sql As String) As String
'first i'd avoid putting quote chars in as they might be valid? just double them up.
Dim strIllegalChars As String = "/?-^%{}[];$=*`#|&#\<>()+,\"
'replace single quotes with double so they don't cause escape character
If sql.Contains("'") Then
sql = sql.Replace("'", "''")
End If
'need to double up double quotes from what I remember to get them through
If sql.Contains("""") Then
sql = sql.Replace("""", """""")
End If
'remove illegal chars
For Each c As Char In strIllegalChars
If sql.Contains(c.ToString) Then
sql = sql.Replace(c.ToString, "")
End If
Next
Return sql
End Function
This hasn't been tested and it could probably be made more efficient, but it should get you going. Wherever you execute your sql in your app, just wrap the sql in this function to clean the string before execution:
ExecuteSQL(MakeSQLSafe(strSQL))
Hope that helps
As with any string sanitisation, you're much better off working with a whitelist that dictates which characters are allowed, rather than a blacklist of characters that aren't.
This question about filtering HTML tags resulted in an accepted answer suggesting the use of a regular expression to match against a whitelist: How do I filter all HTML tags except a certain whitelist? - I suggest you do something very similar.
I'm using URL Routing and I found this works well, pass each part of your URL to this function. It's more than you need as it converts characters like "&" to "and", but you can modify it to suit:
public static string CleanUrl(this string urlpart) {
// convert accented characters to regular ones
string cleaned = urlpart.Trim().anglicized();
// do some pretty conversions
cleaned = Regex.Replace(cleaned, " ", "-");
cleaned = Regex.Replace(cleaned, "#", "no.");
cleaned = Regex.Replace(cleaned, "&", "and");
cleaned = Regex.Replace(cleaned, "%", "percent");
cleaned = Regex.Replace(cleaned, "#", "at");
// strip all illegal characters like punctuation
cleaned = Regex.Replace(cleaned, "[^A-Za-z0-9- ]", "");
// convert spaces to dashes
cleaned = Regex.Replace(cleaned, " +", "-");
// If we're left with nothing after everything is stripped and cleaned
if (cleaned.Length == 0)
cleaned = "no-description";
// return lowercased string
return cleaned.ToLower();
}
// Convert accented characters to standardized ones
private static string anglicized(this string urlpart) {
string beforeConversion = "àÀâÂäÄáÁéÉèÈêÊëËìÌîÎïÏòÒôÔöÖùÙûÛüÜçÇ’ñ";
string afterConversion = "aAaAaAaAeEeEeEeEiIiIiIoOoOoOuUuUuUcC'n";
string cleaned = urlpart;
for (int i = 0; i < beforeConversion.Length; i++) {
cleaned = Regex.Replace(urlpart, afterConversion[i].ToString(), afterConversion[i].ToString());
}
return cleaned;
// Spanish : ÁÉÍÑÓÚÜ¡¿áéíñóúü"
}