How can I check if an NSString contains another substring, at which point it will return a Boolean Value.
This is what I'm thinking of:
If myString.contains("string") then
{
//Stuff Happens
}
But, from the research I've done, it seems as if Obj-C has no function for this. This Wikipedia article gives numerous string functions, their differences, and all in different languages, but I see no Obj-C support for any Contain Function.
Does anyone know of a simple-to-use function like the once above (which is similar to the C# and VB.NET function)?
Would a "Find" Function work? If so, how?
If this is not supported in Obj-C, is there a workaround I can use?
Any help is very appreciated.
if ([myString rangeOfString:#"string"].location != NSNotFound)
{
// Stuff happens
}
NSString *someString = #"Time for an egg hunt";
if ( [someString rangeOfString:#"egg" options:NSCaseInsensitiveSearch].location != NSNotFound ) {
NSLog( #"Found it!" );
}
If you want to be case insensitive.
NSRange range = [string rangeOfString:#"string" options:NSCaseInsensitiveSearch];
if (range.location != NSNotFound)
{
return range.location;
}
else
{
return nil;
}
Documentation
Create a NSString category, and put that in...
Code :
- (BOOL)contains:(NSString *)str
{
NSRange aRange = [self rangeOfString:str];
return (aRange.location!=NSNotFound);
}
Usage :
NSString* testStr = #"This is my string";
if ([testStr contains:#"is"])
{
// do something
}
if([string rangeOfString:substring].length > 0)
...
Given a UIColor, I need to determine if it is "light" or "dark". If I could access the hex value of the color, I could just check if it was greater than or less than a certain threshold hex number, but there appears to be no way to do that. Is there? Or is there another way I could check the brightness value of a UIColor?
You could install this Category for extending UIColor for knowing HSV/HSB and compare [aUIColor brightness]
Edit:
I found the same code in some github-hosted project, made a gist of it: https://gist.github.com/1252197
#import "UIColor-HSVAdditions.h"
#implementation UIColor (UIColor_HSVAdditions)
+(struct hsv_color)HSVfromRGB:(struct rgb_color)rgb
{
struct hsv_color hsv;
CGFloat rgb_min, rgb_max;
rgb_min = MIN3(rgb.r, rgb.g, rgb.b);
rgb_max = MAX3(rgb.r, rgb.g, rgb.b);
hsv.val = rgb_max;
if (hsv.val == 0) {
hsv.hue = hsv.sat = 0;
return hsv;
}
rgb.r /= hsv.val;
rgb.g /= hsv.val;
rgb.b /= hsv.val;
rgb_min = MIN3(rgb.r, rgb.g, rgb.b);
rgb_max = MAX3(rgb.r, rgb.g, rgb.b);
hsv.sat = rgb_max - rgb_min;
if (hsv.sat == 0) {
hsv.hue = 0;
return hsv;
}
if (rgb_max == rgb.r) {
hsv.hue = 0.0 + 60.0*(rgb.g - rgb.b);
if (hsv.hue < 0.0) {
hsv.hue += 360.0;
}
} else if (rgb_max == rgb.g) {
hsv.hue = 120.0 + 60.0*(rgb.b - rgb.r);
} else /* rgb_max == rgb.b */ {
hsv.hue = 240.0 + 60.0*(rgb.r - rgb.g);
}
return hsv;
}
-(CGFloat)hue
{
struct hsv_color hsv;
struct rgb_color rgb;
rgb.r = [self red];
rgb.g = [self green];
rgb.b = [self blue];
hsv = [UIColor HSVfromRGB: rgb];
return (hsv.hue / 360.0);
}
-(CGFloat)saturation
{
struct hsv_color hsv;
struct rgb_color rgb;
rgb.r = [self red];
rgb.g = [self green];
rgb.b = [self blue];
hsv = [UIColor HSVfromRGB: rgb];
return hsv.sat;
}
-(CGFloat)brightness
{
struct hsv_color hsv;
struct rgb_color rgb;
rgb.r = [self red];
rgb.g = [self green];
rgb.b = [self blue];
hsv = [UIColor HSVfromRGB: rgb];
return hsv.val;
}
-(CGFloat)value
{
return [self brightness];
}
#end
[UIColor CGColor] will get you a CGColorRef, from there you can do CGColorGetComponents to get the individual components. Getting the "brightness" value depends on your definition of brightness. Getting an average of the components (in case of RGB color space) might be a good start.
UIColor (and CGColorRef) are generally described in RGB values. If you want to determine light or dark, you'll probably want to convert these values to something like Hue/Saturation/Brightness. But there are no built in functions like you are looking for.
here is a guide (with code provided) on UIColor expansion (using a category) and has methods such as get hexStringFromColor: It should be what you're looking for. UIColor expansion Note: I did not write this blog or code.
Proposed algorithm to calculate color / color brightness difference: http://maestric.com/doc/color_brightness_difference_calculator
(based on w3c paper)
How to check if the content of a NSString is an integer value? Is there any readily available way?
There got to be some better way then doing something like this:
- (BOOL)isInteger:(NSString *)toCheck {
if([toCheck intValue] != 0) {
return true;
} else if([toCheck isEqualToString:#"0"]) {
return true;
} else {
return false;
}
}
You could use the -intValue or -integerValue methods. Returns zero if the string doesn't start with an integer, which is a bit of a shame as zero is a valid value for an integer.
A better option might be to use [NSScanner scanInt:] which returns a BOOL indicating whether or not it found a suitable value.
Something like this:
NSScanner* scan = [NSScanner scannerWithString:toCheck];
int val;
return [scan scanInt:&val] && [scan isAtEnd];
Building on an answer from #kevbo, this will check for integers >= 0:
if (fooString.length <= 0 || [fooString rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]].location != NSNotFound) {
NSLog(#"This is not a positive integer");
}
A swift version of the above:
func getPositive(incoming: String) -> String {
if (incoming.characters.count <= 0) || (incoming.rangeOfCharacterFromSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet) != nil) {
return "This is NOT a positive integer"
}
return "YES! +ve integer"
}
Do not forget numbers with decimal point!!!
NSMutableCharacterSet *carSet = [NSMutableCharacterSet characterSetWithCharactersInString:#"0123456789."];
BOOL isNumber = [[subBoldText stringByTrimmingCharactersInSet:carSet] isEqualToString:#""];
func getPositive(input: String) -> String {
if (input.count <= 0) || (input.rangeOfCharacter(from: NSCharacterSet.decimalDigits.inverted) != nil) {
return "This is NOT a positive integer"
}
return "YES! integer"
}
Update #coco's answer for Swift 5
I am writing an application that receives data with items and version numbers. The numbers are formatted like "1.0.1" or "1.2.5". How can I compare these version numbers? I think they have to be formatted as a string first, no? What options do I have to determine that "1.2.5" comes after "1.0.1"?
This is the simplest way to compare versions, keeping in mind that "1" < "1.0" < "1.0.0":
NSString* requiredVersion = #"1.2.0";
NSString* actualVersion = #"1.1.5";
if ([requiredVersion compare:actualVersion options:NSNumericSearch] == NSOrderedDescending) {
// actualVersion is lower than the requiredVersion
}
I'll add my method, which compares strictly numeric versions (no a, b, RC etc.) with any number of components.
+ (NSComparisonResult)compareVersion:(NSString*)versionOne toVersion:(NSString*)versionTwo {
NSArray* versionOneComp = [versionOne componentsSeparatedByString:#"."];
NSArray* versionTwoComp = [versionTwo componentsSeparatedByString:#"."];
NSInteger pos = 0;
while ([versionOneComp count] > pos || [versionTwoComp count] > pos) {
NSInteger v1 = [versionOneComp count] > pos ? [[versionOneComp objectAtIndex:pos] integerValue] : 0;
NSInteger v2 = [versionTwoComp count] > pos ? [[versionTwoComp objectAtIndex:pos] integerValue] : 0;
if (v1 < v2) {
return NSOrderedAscending;
}
else if (v1 > v2) {
return NSOrderedDescending;
}
pos++;
}
return NSOrderedSame;
}
This is an expansion to Nathan de Vries answer to address the problem of 1 < 1.0 < 1.0.0 etc.
First off we can address the problem of extra ".0"'s on our version string with an NSString category:
#implementation NSString (VersionNumbers)
- (NSString *)shortenedVersionNumberString {
static NSString *const unnecessaryVersionSuffix = #".0";
NSString *shortenedVersionNumber = self;
while ([shortenedVersionNumber hasSuffix:unnecessaryVersionSuffix]) {
shortenedVersionNumber = [shortenedVersionNumber substringToIndex:shortenedVersionNumber.length - unnecessaryVersionSuffix.length];
}
return shortenedVersionNumber;
}
#end
With the above NSString category we can shorten our version numbers to drop the unnecessary .0's
NSString* requiredVersion = #"1.2.0";
NSString* actualVersion = #"1.1.5";
requiredVersion = [requiredVersion shortenedVersionNumberString]; // now 1.2
actualVersion = [actualVersion shortenedVersionNumberString]; // still 1.1.5
Now we can still use the beautifully simple approach proposed by Nathan de Vries:
if ([requiredVersion compare:actualVersion options:NSNumericSearch] == NSOrderedDescending) {
// actualVersion is lower than the requiredVersion
}
I made it myself,use Category..
Source..
#implementation NSString (VersionComparison)
- (NSComparisonResult)compareVersion:(NSString *)version{
NSArray *version1 = [self componentsSeparatedByString:#"."];
NSArray *version2 = [version componentsSeparatedByString:#"."];
for(int i = 0 ; i < version1.count || i < version2.count; i++){
NSInteger value1 = 0;
NSInteger value2 = 0;
if(i < version1.count){
value1 = [version1[i] integerValue];
}
if(i < version2.count){
value2 = [version2[i] integerValue];
}
if(value1 == value2){
continue;
}else{
if(value1 > value2){
return NSOrderedDescending;
}else{
return NSOrderedAscending;
}
}
}
return NSOrderedSame;
}
Test..
NSString *version1 = #"3.3.1";
NSString *version2 = #"3.12.1";
NSComparisonResult result = [version1 compareVersion:version2];
switch (result) {
case NSOrderedAscending:
case NSOrderedDescending:
case NSOrderedSame:
break;
}
Sparkle (the most popular software update framework for MacOS) has a SUStandardVersionComparator class that does this, and also takes into account build numbers and beta markers. I.e. it correctly compares 1.0.5 > 1.0.5b7 or 2.0 (2345) > 2.0 (2100). The code only uses Foundation, so should work fine on iOS as well.
Check out my NSString category that implements easy version checking on github; https://github.com/stijnster/NSString-compareToVersion
[#"1.2.2.4" compareToVersion:#"1.2.2.5"];
This will return a NSComparisonResult which is more accurate then using;
[#"1.2.2" compare:#"1.2.2.5" options:NSNumericSearch]
Helpers are also added;
[#"1.2.2.4" isOlderThanVersion:#"1.2.2.5"];
[#"1.2.2.4" isNewerThanVersion:#"1.2.2.5"];
[#"1.2.2.4" isEqualToVersion:#"1.2.2.5"];
[#"1.2.2.4" isEqualOrOlderThanVersion:#"1.2.2.5"];
[#"1.2.2.4" isEqualOrNewerThanVersion:#"1.2.2.5"];
Swift 2.2 Version :
let currentStoreAppVersion = "1.10.2"
let minimumAppVersionRequired = "1.2.2"
if currentStoreAppVersion.compare(minimumAppVersionRequired, options: NSStringCompareOptions.NumericSearch) ==
NSComparisonResult.OrderedDescending {
print("Current Store version is higher")
} else {
print("Latest New version is higher")
}
Swift 3 Version :
let currentStoreVersion = "1.1.0.2"
let latestMinimumAppVersionRequired = "1.1.1"
if currentStoreVersion.compare(latestMinimumAppVersionRequired, options: NSString.CompareOptions.numeric) == ComparisonResult.orderedDescending {
print("Current version is higher")
} else {
print("Latest version is higher")
}
I thought I'd just share a function I pulled together for this. It is not perfect at all. Please take a look that the examples and results. But if you are checking your own version numbers (which I have to do to manage things like database migrations) then this may help a little.
(also, remove the log statements in the method, of course. those are there to help you see what it does is all)
Tests:
[self isVersion:#"1.0" higherThan:#"0.1"];
[self isVersion:#"1.0" higherThan:#"0.9.5"];
[self isVersion:#"1.0" higherThan:#"0.9.5.1"];
[self isVersion:#"1.0.1" higherThan:#"1.0"];
[self isVersion:#"1.0.0" higherThan:#"1.0.1"];
[self isVersion:#"1.0.0" higherThan:#"1.0.0"];
// alpha tests
[self isVersion:#"1.0b" higherThan:#"1.0a"];
[self isVersion:#"1.0a" higherThan:#"1.0b"];
[self isVersion:#"1.0a" higherThan:#"1.0a"];
[self isVersion:#"1.0" higherThan:#"1.0RC1"];
[self isVersion:#"1.0.1" higherThan:#"1.0RC1"];
Results:
1.0 > 0.1
1.0 > 0.9.5
1.0 > 0.9.5.1
1.0.1 > 1.0
1.0.0 < 1.0.1
1.0.0 == 1.0.0
1.0b > 1.0a
1.0a < 1.0b
1.0a == 1.0a
1.0 < 1.0RC1 <-- FAILURE
1.0.1 < 1.0RC1 <-- FAILURE
notice that alpha works but you have to be very careful with it. once you go alpha at some point you cannot extend that by changing any other minor numbers behind it.
Code:
- (BOOL) isVersion:(NSString *)thisVersionString higherThan:(NSString *)thatVersionString {
// LOWER
if ([thisVersionString compare:thatVersionString options:NSNumericSearch] == NSOrderedAscending) {
NSLog(#"%# < %#", thisVersionString, thatVersionString);
return NO;
}
// EQUAL
if ([thisVersionString compare:thatVersionString options:NSNumericSearch] == NSOrderedSame) {
NSLog(#"%# == %#", thisVersionString, thatVersionString);
return NO;
}
NSLog(#"%# > %#", thisVersionString, thatVersionString);
// HIGHER
return YES;
}
My iOS library AppUpdateTracker contains an NSString category to perform this sort of comparison. (Implementation is based off DonnaLea's answer.)
Usage would be as follows:
[#"1.4" isGreaterThanVersionString:#"1.3"]; // YES
[#"1.4" isLessThanOrEqualToVersionString:#"1.3"]; // NO
Additionally, you can use it to keep track of your app's installation/update status:
[AppUpdateTracker registerForAppUpdatesWithBlock:^(NSString *previousVersion, NSString *currentVersion) {
NSLog(#"app updated from: %# to: %#", previousVersion, currentVersion);
}];
[AppUpdateTracker registerForFirstInstallWithBlock:^(NSTimeInterval installTimeSinceEpoch, NSUInteger installCount) {
NSLog(#"first install detected at: %f amount of times app was (re)installed: %lu", installTimeSinceEpoch, (unsigned long)installCount);
}];
[AppUpdateTracker registerForIncrementedUseCountWithBlock:^(NSUInteger useCount) {
NSLog(#"incremented use count to: %lu", (unsigned long)useCount);
}];
Here is the swift 4.0 + code for version comparison
let currentVersion = "1.2.0"
let oldVersion = "1.1.1"
if currentVersion.compare(oldVersion, options: NSString.CompareOptions.numeric) == ComparisonResult.orderedDescending {
print("Higher")
} else {
print("Lower")
}
Glibc has a function strverscmp and versionsort… unfortunately, not portable to the iPhone, but you can write your own fairly easily. This (untested) re-implementation comes from just reading the documented behavior, and not from reading Glibc's source code.
int strverscmp(const char *s1, const char *s2) {
const char *b1 = s1, *b2 = s2, *e1, *e2;
long n1, n2;
size_t z1, z2;
while (*b1 && *b1 == *b2) b1++, b2++;
if (!*b1 && !*b2) return 0;
e1 = b1, e2 = b2;
while (b1 > s1 && isdigit(b1[-1])) b1--;
while (b2 > s2 && isdigit(b2[-1])) b2--;
n1 = strtol(b1, &e1, 10);
n2 = strtol(b2, &e2, 10);
if (b1 == e1 || b2 == e2) return strcmp(s1, s2);
if (n1 < n2) return -1;
if (n1 > n2) return 1;
z1 = strspn(b1, "0"), z2 = strspn(b2, "0");
if (z1 > z2) return -1;
if (z1 < z2) return 1;
return 0;
}
If you know each version number will have exactly 3 integers separated by dots, you can parse them (e.g. using sscanf(3)) and compare them:
const char *version1str = "1.0.1";
const char *version2str = "1.2.5";
int major1, minor1, patch1;
int major2, minor2, patch2;
if(sscanf(version1str, "%d.%d.%d", &major1, &minor1, &patch1) == 3 &&
sscanf(version2str, "%d.%d.%d", &major2, &minor2, &patch2) == 3)
{
// Parsing succeeded, now compare the integers
if(major1 > major2 ||
(major1 == major2 && (minor1 > minor2 ||
(minor1 == minor2 && patch1 > patch2))))
{
// version1 > version2
}
else if(major1 == major2 && minor1 == minor2 && patch1 == patch2)
{
// version1 == version2
}
else
{
// version1 < version2
}
}
else
{
// Handle error, parsing failed
}
To check the version in swift you can use following
switch newVersion.compare(currentversion, options: NSStringCompareOptions.NumericSearch) {
case .OrderedDescending:
println("NewVersion available ")
// Show Alert Here
case .OrderedAscending:
println("NewVersion Not available ")
default:
println("default")
}
Hope it might be helpful.
Here is a recursive function that do the works with multiple version formatting of any length. It also works for #"1.0" and #"1.0.0"
static inline NSComparisonResult versioncmp(const NSString * a, const NSString * b)
{
if ([a isEqualToString:#""] && [b isEqualToString:#""]) {
return NSOrderedSame;
}
if ([a isEqualToString:#""]) {
a = #"0";
}
if ([b isEqualToString:#""]) {
b = #"0";
}
NSArray<NSString*> * aComponents = [a componentsSeparatedByString:#"."];
NSArray<NSString*> * bComponents = [b componentsSeparatedByString:#"."];
NSComparisonResult r = [aComponents[0] compare:bComponents[0] options:NSNumericSearch];
if(r != NSOrderedSame) {
return r;
} else {
NSString* newA = (a.length == aComponents[0].length) ? #"" : [a substringFromIndex:aComponents[0].length+1];
NSString* newB = (b.length == bComponents[0].length) ? #"" : [b substringFromIndex:bComponents[0].length+1];
return versioncmp(newA, newB);
}
}
Test samples :
versioncmp(#"11.5", #"8.2.3");
versioncmp(#"1.5", #"8.2.3");
versioncmp(#"1.0", #"1.0.0");
versioncmp(#"11.5.3.4.1.2", #"11.5.3.4.1.2");
Based on #nathan-de-vries 's answer, I wrote SemanticVersion.swift for comparing Semantic Version, and here is the test cases.
How to check if the content of a NSString is an integer value? Is there any readily available way?
There got to be some better way then doing something like this:
- (BOOL)isInteger:(NSString *)toCheck {
if([toCheck intValue] != 0) {
return true;
} else if([toCheck isEqualToString:#"0"]) {
return true;
} else {
return false;
}
}
You could use the -intValue or -integerValue methods. Returns zero if the string doesn't start with an integer, which is a bit of a shame as zero is a valid value for an integer.
A better option might be to use [NSScanner scanInt:] which returns a BOOL indicating whether or not it found a suitable value.
Something like this:
NSScanner* scan = [NSScanner scannerWithString:toCheck];
int val;
return [scan scanInt:&val] && [scan isAtEnd];
Building on an answer from #kevbo, this will check for integers >= 0:
if (fooString.length <= 0 || [fooString rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]].location != NSNotFound) {
NSLog(#"This is not a positive integer");
}
A swift version of the above:
func getPositive(incoming: String) -> String {
if (incoming.characters.count <= 0) || (incoming.rangeOfCharacterFromSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet) != nil) {
return "This is NOT a positive integer"
}
return "YES! +ve integer"
}
Do not forget numbers with decimal point!!!
NSMutableCharacterSet *carSet = [NSMutableCharacterSet characterSetWithCharactersInString:#"0123456789."];
BOOL isNumber = [[subBoldText stringByTrimmingCharactersInSet:carSet] isEqualToString:#""];
func getPositive(input: String) -> String {
if (input.count <= 0) || (input.rangeOfCharacter(from: NSCharacterSet.decimalDigits.inverted) != nil) {
return "This is NOT a positive integer"
}
return "YES! integer"
}
Update #coco's answer for Swift 5