objective-c中的NSString操作

objective-c中的NSString操作

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//1、创建常量字符串。

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

//2、创建空字符串，给予赋值。

NSString *astring = [[NSString alloc] init];

astring = @"This is a String!";

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

[astring release];

//3、在以上方法中，提升速度:initWithString方法

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];

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

[astring release];

//4、用标准c创建字符串:initWithCString方法

char *Cstring = "This is a String!";

NSString *astring = [[NSString alloc] initWithCString:Cstring];

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

[astring release];

//5、创建格式化字符串:占位符（由一个%加一个字符组成）

int i = 1;

int j = 2;

NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];

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

[astring release];

//6、创建临时字符串

NSString *astring;

astring = [NSString stringWithCString:"This is a temporary string"];

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

NSString *path = @"astring.text";

NSString *astring = [[NSString alloc] initWithContentsOfFile:path];

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

[astring release];

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];

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

NSString *path = @"astring.text";

[astring writeToFile: path atomically: YES];

[astring release];

//用C比较:strcmp函数

char string1[] = "string!";

char string2[] = "string!";

if(strcmp(string1, string2) = = 0)

{

NSLog(@"1");

}

//isEqualToString方法

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

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

BOOL result = [astring01 isEqualToString:astring02];

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

//compare方法(comparer返回的三种值)

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

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

BOOL result = [astring01 compare:astring02] = = NSOrderedSame;

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

//NSOrderedSame 判断两者内容是否相同

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

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

BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;

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

//NSOrderedAscending 判断两对象值的大小(按字母顺序进行比较，astring02大于astring01为真)

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

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

BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;

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

//NSOrderedDescending 判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//不考虑大 小写比较字符串1

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

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

BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;

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

//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//如何判断字符串为空

NSString *urlString = [urlInput stringValue];

if (!urlString) {

NSLog( @”NO INPUT.” );

} else {

if ([urlString length] == 0 ) {

NSLog( @”NO INPUT.” );

} else {

}

}

}

Convert NSString to int

Convert int to NSString