iOS NSString的常用用法-GeekBand

*创建

NSString *str1 = @"Hello World!";

NSString *str2 = [[NSString alloc]initWithCString:"Hello World!" encoding:NSUTF8StringEncoding];

NSString *str3 = [NSString stringWithCString:"Hello World!" encoding:NSUTF8StringEncoding];

NSString *str4= @"Hello World!";

*常用数值比较

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 isEqualToString:astring02];

NSLog(@"result:%d",result);

*伪更改：返回新字符串

str1=[str1 stringByAppendingString:@" Yes!"];

NSRange stringRange = NSMakeRange(12, 4);

str1=[str1 stringByReplacingCharactersInRange:stringRange withString:@"Good"];

NSLog(@"after change... str1=%@",str1);

NSLog(@"str1:%p",str1);

*NSMutableString的可变性

NSMutableString *mustr1 = [NSMutableString stringWithString: @"Hello,World!"];

NSLog(@"mustr1:%p",mustr1);

NSMutableString *mustr2 = [NSMutableString stringWithString: @"Hello,World!"];

NSLog(@"mustr2:%p",mustr2);

NSString *str5=mustr1;

NSLog(@"str5:%@",str5);

[mustr1 appendString:@" Very Good!"];

NSLog(@"str5:%@",str5);

*NSMutableString的增删改查方法

NSMutableString *mustr3 =[NSMutableString stringWithCapacity:100];

[mustr3 appendString:@"Hello Objective"];

[mustr3 insertString:@"-C" atIndex:mustr3.length];

[mustr3 setString:@"Hi Objective"];

NSRange replaceRange = NSMakeRange(0, 2);

[mustr3 replaceCharactersInRange:replaceRange withString:@"Hello"];

NSRange deleteRange = NSMakeRange(5, 10);

[mustr3 deleteCharactersInRange:deleteRange];