NSCharacterSet-字符集使用總結(jié)

簡介

NSCharacterSet ,以及它的可變類型 NSMutableCharacterSet,用面向?qū)ο蟮姆绞絹肀硎疽唤MUnicode字符。它經(jīng)常與NSString及NSScanner組合起來使用,在不同的字符上做過濾、刪除或者分割操作。

方法和屬性介紹:

NSCharacterSet 中提供的下面屬性都是只讀的, 且在NSMutableCharacterSet中有一致的類方法

1.controlCharacterSet //控制符的字符集

2.whitespaceCharacterSet //空格的字符集

3.whitespaceAndNewlineCharacterSet //空格和換行符的字符集

4.decimalDigitCharacterSet //十進(jìn)制數(shù)字的字符集

5.letterCharacterSet //字母的字符集

6.lowercaseLetterCharacterSet //小寫字母的字符集

7.uppercaseLetterCharacterSet //大寫字母的字符集

8.nonBaseCharacterSet //非基礎(chǔ)的字符集

9.alphanumericCharacterSet //字母和數(shù)字的字符集

10.decomposableCharacterSet //可分解

11.illegalCharacterSet //非法的字符集

12.punctuationCharacterSet //標(biāo)點(diǎn)的字符集

13.capitalizedLetterCharacterSet //首字母大寫的字符集

14.symbolCharacterSet //符號的字符集

15.newlineCharacterSet //換行符的字符集

NSCharacterSet 和 NSMutableCharacterSet一致的類方法

//返回一個(gè)指定范圍的字符集,取自小寫字母字符集

+ (NSCharacterSet *)characterSetWithRange:(NSRange)aRange;

//返回一個(gè)包含當(dāng)前字符串的字符集

+ (NSCharacterSet *)characterSetWithCharactersInString:(NSString *)aString;

//返回包含由給定位圖表示形式確定的字符的字符集,此方法對于使用來自文件或其他外部數(shù)據(jù)源的數(shù)據(jù)創(chuàng)建字符集

+ (NSCharacterSet *)characterSetWithBitmapRepresentation:(NSData *)data;

//返回從位圖表示中讀取的字符集,存儲在文件中給定的路徑。

+ (nullable NSCharacterSet *)characterSetWithContentsOfFile:(NSString *)fName;




NSCharacterSet中的其它方法或?qū)傩裕?/b>

//指定字符集是包含于在于當(dāng)前字符集

- (BOOL)characterIsMember:(unichar)aCharacter;

//以二進(jìn)制格式編碼接收器的NSData對象,此格式適用于保存到文件或以其他方式傳輸或歸檔

@property (readonly, copy) NSData *bitmapRepresentation;

//反轉(zhuǎn)字符集,僅包含當(dāng)前字符集中不存在的字符

@property (readonly, copy) NSCharacterSet *invertedSet;


NSMutableCharacterSet中其它方法:

- (void)addCharactersInRange:(NSRange)aRange;

- (void)removeCharactersInRange:(NSRange)aRange;

- (void)addCharactersInString:(NSString *)aString;

- (void)removeCharactersInString:(NSString *)aString;

- (void)formUnionWithCharacterSet:(NSCharacterSet *)otherSet;

- (void)formIntersectionWithCharacterSet:(NSCharacterSet *)otherSet;

- (void)invert;

//*****************************************

延伸常與NSString 的一些方法結(jié)合使用, 來達(dá)到某些效果

//返回一個(gè)指定字符集分隔開的子字符串?dāng)?shù)組

- (NSArray*)componentsSeparatedByCharactersInSet:(NSCharacterSet *)separator NS_AVAILABLE(10_5, 2_0);

//返回一個(gè)去除兩端指定字符集的字符串

- (NSString *)stringByTrimmingCharactersInSet:(NSCharacterSet *)set;

//返回指定字符集在當(dāng)前字符串中的第一個(gè)符合條件的范圍

- (NSRange)rangeOfCharacterFromSet:(NSCharacterSet *)searchSet;

NSArray的一些方法:

//在數(shù)組中子串之間插入指定字符

- (NSString *)componentsJoinedByString:(NSString *)separator;

應(yīng)用

NSString *testString = @"This is the test string for %a*b*c&";

NSArray *divArr = [testString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"abc"]];

NSLog(@"%@",divArr);

打印結(jié)果:

(

"This is the test string for %",

"*",

"*",

"&"

)


舉例使用

1.去掉首尾空格

NSString *testString = @"? ? ? This is the string contains whitespace in beginning and ending? ? ";

NSString *whitesspaceStr = [testString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

NSLog(@"%@",whitesspaceStr);


打印結(jié)果: This is the string contains whitespace in beginning and ending

2.去除首尾指定字符串

NSString *str=@"哈哈呵呵嘿嘿吼吼";

NSCharacterSet *cs= [NSCharacterSet characterSetWithCharactersInString:@"哈吼"];

NSString *strResult = [str stringByTrimmingCharactersInSet:cs];

NSLog(@"%@",strResult);


打印結(jié)果: 呵呵嘿嘿

3.用指定字符串替代當(dāng)前字符中的指定字符集中的字符串

NSMutableCharacterSet *letter = [NSMutableCharacterSet lowercaseLetterCharacterSet];

NSCharacterSet *decimalDigit = [NSCharacterSet decimalDigitCharacterSet];

[letter formUnionWithCharacterSet:decimalDigit];

NSString *string = @"g8!hgr3@09#23uiq%^78sjn453t78&13gesg*wt53(545y45)q3at";

NSLog(@"%@",[[string componentsSeparatedByCharactersInSet:letter] componentsJoinedByString:@"_"]);

[letter invert];? //字母數(shù)字反轉(zhuǎn)

NSLog(@"%@",[[string componentsSeparatedByCharactersInSet:letter] componentsJoinedByString:@"_"]);


打印結(jié)果:

__!____@__#_____%^___________&______*____(______)____

g8_hgr3_09_23uiq__78sjn453t78_13gesg_wt53_545y45_q3at


4.去除所有空格

NSString *string = @"? a b? cd? ef gh ij? ? klm? nopq rstu v? w x? y z? ";

NSLog(@"%@",[[string componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] componentsJoinedByString:@""]);


打印結(jié)果: abcdefghijklmnopqrstuvwxyz

5.與NSPredicate結(jié)合使用壓縮空格

NSString *string = @"? Additional? ? setup? after? ? loading the? ? view.";

string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

NSArray *components = [string componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

components = [components filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"self <> ''"]];

string = [components componentsJoinedByString:@" "];

NSLog(@"%@", string);


打印結(jié)果: Additional setup after loading the view.

6.判斷字符串是否只包含數(shù)字

- (BOOL)validateNumber:(NSString*)number {

BOOL res = YES;

NSCharacterSet* tmpSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];

int i = 0;

while (i < number.length) {

NSString * string = [number substringWithRange:NSMakeRange(i, 1)];

NSRange range = [string rangeOfCharacterFromSet:tmpSet];

if (range.length == 0) {

res = NO;

break;

}

i++;

}

return res;

}


7.在UITextFieldDelegate方法中, 限制只能輸入數(shù)字和小數(shù)點(diǎn), 且第一位不可以輸入小數(shù)點(diǎn), 小數(shù)點(diǎn)只能輸入一個(gè)

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

NSCharacterSet *cs;

NSUInteger nDotLoc = [textField.text rangeOfString:@"."].location;

if (NSNotFound == nDotLoc && 0 != range.location) {

cs = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789."] invertedSet];

}else{

cs = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789"] invertedSet];

}

NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];

BOOL basicTest = [string isEqualToString:filtered];

if (!basicTest) {

return NO;

}

return YES;

}

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