字符串
創(chuàng)建字符串
+ (id) stringWithFormat: (NSString *) format,...;//此處stringWithFormat:是一個(gè)工廠方法
NSString *height ; height= [NSString stringWithFormat:@"Your height is %d feet,%d feet, %d inches",5,11];
字符串比較
- (BOOL) osEqualToString:(NSString *)aString; //實(shí)例方法 比較兩個(gè)字符串內(nèi)容是否相同
NSString *thing1 = @"hello 5"; NSString *thing2=[NSString stringWithFormat: @"hello %d",5]; if([thing1 isEqualToString: thing2]) { NSLog(@"They are the same!"); }
- (NSComparisonResult) compare: (NSString *) aString;
//compare:將接收對(duì)象和傳遞過(guò)來(lái)的字符串逐個(gè)進(jìn)行比較(區(qū)分大小寫(xiě))，顯示孰大孰小
//其返回類型為一個(gè)enum型枚舉，如下所示
enum{
NSOrderedAscending = -1,
NSOrderedSame,
NSOrderedDescending
};
typedef NSInteger NSComparisonResult;
不區(qū)分大小寫(xiě)的比較
- (NSComparisonResult) compare: (NSString *) aString options: (NSStringCompareOptions) mask;
//其中常用的mask選項(xiàng)如下:
NSCaseInsensitiveSearch:不區(qū)分大小寫(xiě)字符
NSLiteralSearch:進(jìn)行完全比較绽慈，區(qū)分大小寫(xiě)
NSNumericSearch:比較字符串的字符個(gè)數(shù)
字符串內(nèi)是否包含別的字符串
- (BOOL) hasPrefix: (NSString *) aString;
- (BOOL) hasSuffix: (NSString *) aString;
- (BOOL) rangOfString: (NSString *) aString;
可變性
+ (id) stringWithCapacity: (NSUInteger) capacity;
- (void) appendString: (NSString *) aString;
- (void) appendFormat: (NSString *) format, ...;
- (void) deleteCharactersInRange: (NSRange) aRange;