1. String cutting
1. Strings with nodes, such as @"<p>Nevious nodes<br/></p>"We only want the Chinese in the middle
How to deal with it:
Copy the codeThe code is as follows:
NSString *string1 = @"<p>Neering Node<br/></p>";
/*Put all unwanted characters into characterSet1 here, without adding commas or spaces, unless there are spaces you want to remove in the string, <p/ etc. are all present separately and are not used as the entire character*/
NSCharacterSet *characterSet1 = [NSCharacterSet characterSetWithCharactersInString:@"<p/brh>"];
// Divide string1 into an array according to the elements in characterSet1
NSArray *array1 = [string1 componentsSeparatedByCharactersInSet:characterSet1];
NSLog(@"array = %@",array1);
for(NSString *string1 in array1)
{
if ([string1 length]>0) {
// Here string is a Chinese string
NSLog(@"string = %@",string1);
}
}
Print result:
2016-01-17 10:55:34.017 string[17634:303] array = ( "", "", "", "\U8ba8\U538c\U7684\U8282\U70b9", "", "", "", "", "", "", "", "", "" ) 2016-01-17 10:55:34.049 string[17634:303] string = Annoying nodes
2. A string with spaces, such as
@"hello world" Remove spaces
Copy the codeThe code is as follows:
NSString *string2 = @"hello world";
/*Processing spaces*/
NSCharacterSet *characterSet2 = [NSCharacterSet whitespaceCharacterSet];
// Divide string1 into an array according to the elements in characterSet1
NSArray *array2 = [string2 componentsSeparatedByCharactersInSet:characterSet2];
NSLog(@"\narray = %@",array2);
// Used to store processed strings
NSMutableString *newString1 = [NSMutableString string];
for(NSString *string in array1)
{
[newString1 appendString:string];
}
NSLog(@"newString = %@", newString1);
Print result:
2016-01-17 11:02:49.656 string[17889:303] array = ( hello, world ) 2016-01-17 11:02:49.657 string[17889:303] newString = helloworld
PS: To process other elements such as letters, just change the value of the NSCharacterSet.
Copy the codeThe code is as follows:
+ (id)controlCharacterSet;
+ (id)whitespaceCharacterSet;
+ (id)whitespaceAndNewlineCharacterSet;
+ (id)decimalDigitCharacterSet;
+ (id)letterCharacterSet;
+ (id)lowercaseLetterCharacterSet;
+ (id)uppercaseLetterCharacterSet;
+ (id)nonBaseCharacterSet;
+ (id)alphanumericCharacterSet;
+ (id)decomposableCharacterSet;
+ (id)illegalCharacterSet;
+ (id)punctuationCharacterSet;
+ (id)capitalizedLetterCharacterSet;
+ (id)symbolCharacterSet;
+ (id)newlineCharacterSet NS_AVAILABLE(10_5, 2_0);
+ (id)characterSetWithRange:(NSRange)aRange;
+ (id)characterSetWithCharactersInString:(NSString *)aString;
+ (id)characterSetWithBitmapRepresentation:(NSData *)data;
+ (id)characterSetWithContentsOfFile:(NSString *)fName;
2. Use characters to splice elements in NSArray
Copy the codeThe code is as follows:
NSArray *array = [NSArray arrayWithObjects:@"hello",@"world",nil];
//If you want to splice strings with:, etc., just change the @" "space below to @"," or @":"
NSString *string = [array componentsJoinedByString:@" "];
NSLog(@"string = %@",string);
Print result:
hello world
3. Intercept substrings:
Here, taking the time as an example, when using NSDate to obtain the current time, sometimes only the date or only the time is needed.
1. Seize the specified position from the beginning of the string, such as
Copy the codeThe code is as follows:
//Get the current date and time
NSDate *date = [NSDate date];
//Define the date format. NSDate is not focused on here, so it will not be explained in detail. It will be discussed in detail later.
NSDateFormatter *dateformatter = [[NSDateFormatter alloc] init];
//Set date format
[dateformatter setDateFormat:@"YYYY-MM-dd HH:mm"];
//Convert date to NSString type
NSString *string = [dateformatter stringFromDate:date];
NSLog(@"\ncurrent = %@",string);
//Intercepted date substringToIndex
NSString *currentDate = [string substringToIndex:10];
NSLog(@"\ncurrentDate = %@",currentDate);
Print result:
current = 2016-01-1711:12 currentDate = 2016-01-17
2. Extract the intermediate substring-substringWithRange
Copy the codeThe code is as follows:
//Search the month and day
NSString *currentMonthAndDate = [string substringWithRange:[NSMakeRange(5, 5)]];
NSLog(@"currentMonthAndDate = %@",currentMonthAndDate);
Print result:
currentMonthAndDate = 06-27
3. Start intercepting from a certain location - substringFromIndex
Copy the codeThe code is as follows:
//Intercept time substringFromIndex
NSString *currentTime = [string substringFromIndex:11];
NSLog(@"\ncurrentTime = %@",currentTime);\
Print result:
currentTime = 11:25
4. Comparison strings
Copy the codeThe code is as follows:
NSString *first = @"string";
NSString *second = @"String";
1. Determine whether the two strings are the same - isEqualToString method
Copy the codeThe code is as follows:
BOOL isEqual = [first isEqualToString:second];
NSLog(@"first is Equal to second:%@",isEqual);
Print result:
first is Equal to second:0
2. Compare method compares three values of string
Copy the codeThe code is as follows:
NSOrderedSame//is the same
NSOrderedAscending//Ascending order, compared in alphabetical order, greater than is true
NSOrderedDescending// descending order, compare in alphabetical order, less than is true
BOOL result = [first compare:sencond] == NSOrderedSame;
NSLog(@"result:%d",result);
Print result:
result:0
Copy the codeThe code is as follows:
BOOL result = [first compare:second] == NSOrderedAscending;
NSLog(@"result:%d",result);
Print result:
result:0
Copy the codeThe code is as follows:
BOOL result = [first compare:second] == NSOrderedDecending; NSLog(@"result:%d",result);
Print result:
result:1
3. Compare strings without considering upper and lower case
Copy the codeThe code is as follows:
BOOL result = [first compare:second
options:NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame;
NSLog(@"result:%d",result);
Print result:
result:1
5. Change the upper and lower case of strings
Copy the codeThe code is as follows:
NSString *aString = @"A String";
NSString *string = @"String";
//capital
NSLog(@"aString:%@",[aString uppercaseString]);
//lower case
NSLog(@"string:%@",[string lowercaseString]);
//Precision letter uppercase
NSLog(@"string:%@",[string capitalizedString]);
Print result:
aString:A STRING string:string string:String
6. Search for substrings in strings
Copy the codeThe code is as follows:
NSString *string1 = @"This is a string";
NSString *string2 = @"string";
NSRange range = [string1 rangeOfString:string2];
NSUInteger location = ;
NSUInteger leight = ;
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%li,Leight:%li",location,leight]];
NSLog(@"astring:%@",astring);
[astring release];
Print result:
astring:Location:10,Leight:6