1、字符串的初始化
-(void)initStringFun{
//1、使用Unicode数值数组转化成字符串
unichar data[6] = {97,98,99,100,101,102};
NSString * string = [[NSString alloc] initWithCharacters:data length:6];
NSLog(@"string = %@",string);
NSString * str = [NSString stringWithCharacters:data length:6];
NSLog(@"str = %@",str);
//2、将c风格字符串转NSString对象
char * cStr = "hello,iOS";
NSString * cString = [[NSString alloc] initWithUTF8String:cStr];
NSLog(@"cString = %@",cString);
//将oc字符串转为c字符串
const char * strToC = [cString UTF8String];
NSLog(@"strToC = %s",strToC);
}
2、字符串的常用功能
-(void)commonFunction{
//1、追加字符串
NSString * str = @"Hello";
NSString * book = @",book";
NSString * strBook = [str stringByAppendingString:book];
NSLog(@"str = %@",str);
NSLog(@"strBook = %@",strBook);
//2、追加带变量的字符串
NSString * fStr = @"Hello";
NSString * formatStr = [fStr stringByAppendingFormat:@"%@Book",@"Good"];
NSLog(@"fStr = %@",fStr);
NSLog(@"formatStr = %@",formatStr);
//3、字符串的截取
NSString * string = @"hello,this is a good book";
NSString * subStr1 = [string substringToIndex:10];//0-10的子字符串
NSString * subStr2 = [string substringFromIndex:10];//10-末尾的子字符串
NSString * subStr3 = [string substringWithRange:NSMakeRange(2, 3)];//2开始的3个字符长度的字符串
NSLog(@"subStr1 = %@",subStr1);
NSLog(@"subStr2 = %@",subStr2);
NSLog(@"subStr3 = %@",subStr3);
//4、子字符串所在位置及长度
NSString * mainString = @"hello,world";
NSString * subStr = @"world";
NSRange range = [mainString rangeOfString:subStr];
NSLog(@"range.location = %ld,range,length = %ld",range.location,range.length);
//5、字符串统一转大小写
NSString * smallBigStr = @"Hello,World";
NSString * smallStr = [smallBigStr lowercaseString];
NSString * bigStr = [smallBigStr uppercaseString];
NSLog(@"smallStr = %@",smallStr);
NSLog(@"bigStr = %@",bigStr);
//6、字符串前后缀
NSString * preString = @"hello,world";
BOOL hasPre = [preString hasPrefix:@"hello"];
NSLog(@"hasPre = %d",hasPre);
NSString * sufString = @"hello,world";
[sufString hasSuffix:@"world"];
NSLog(@"sufString = %d",hasPre);
//7、字符串长度
NSString * lengthStr = @"hello,world";
NSLog(@"lengthStr.length = %ld",lengthStr.length);
//8、字符串中的字符
NSString * charStr = @"hello,world";
unichar c = [charStr characterAtIndex:0];
NSLog(@"c = %c",c);
//9、字符串的比较
NSString * compareStr1 = @"hello";
NSString * compareStr2 = @"world";
NSComparisonResult result = [compareStr1 compare:compareStr2];
NSLog(@"result = %d",result);
BOOL isEqual = [compareStr1 isEqualToString:compareStr2];
NSLog(@"isEqual = %d",isEqual);
//10、字符串的分割
NSString * sepStr = @"hello-world";
NSArray * setArray = [sepStr componentsSeparatedByString:@"-"];
NSLog(@"setArray = %@",setArray);
NSCharacterSet * charSet = [NSCharacterSet characterSetWithCharactersInString:@"-o"];
NSArray * array = [sepStr componentsSeparatedByCharactersInSet:charSet];
NSLog(@"array = %@",array);
}
3、可变字符串
-(void)mutableStringFun{
NSMutableString * mString = [[NSMutableString alloc] initWithString:@"hello"];
//1、追加字符串
[mString appendString:@",book"];
NSLog(@"mString = %@",mString);
//2、追加带变量的字符串
[mString appendFormat:@".%@ Good Book",@"This Is A"];
NSLog(@"mString = %@",mString);
//3、删除指定位置字符
[mString deleteCharactersInRange:NSMakeRange(0, 6)];
NSLog(@"mString = %@",mString);
//4、替换指定位置字符
[mString replaceCharactersInRange:NSMakeRange(0, 6) withString:@"你好"];
NSLog(@"mString = %@",mString);
//5、在指定位置插入字符
[mString insertString:@"你好" atIndex:7];
NSLog(@"mString = %@",mString);
//6、覆盖字符串
[mString setString:@"你好，世界"];
NSLog(@"mString = %@",mString);
}
4、其它方法
//将int类型 转为16进制的字符串1
-(void)hexStringFromNum{
int num = 16;
NSString *hexString = [NSString stringWithFormat:@"%@",[[NSString alloc] initWithFormat:@"%1x",num]];
NSLog(@"hexString = %@",hexString);
}
//将int类型 转为16进制的字符串2(待验证)
-(void)longlongToHexStr{
NSInteger value = 16;
int len = 2;
char ASSICCHAR[] = "0123456789ABCDEF";;
char resultBuffer[len];
for (int i = 0; i < len; i++) {
resultBuffer[len - i - 1] = ASSICCHAR[(value >> (i * 4)) & 0x0F];
}
NSString * hexString = [NSString stringWithCString:resultBuffer encoding:NSASCIIStringEncoding];
NSLog(@"hexString = %@",hexString);
}
//字典转为json格式字符串
-(NSString*)jsonStringFromDict{
NSDictionary * dict = @{@"1":@"test1",
@"2":@"test3"};
NSData * mData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];
NSString * dictString = [[NSString alloc] initWithData:mData encoding:NSUTF8StringEncoding];
NSLog(@"dictString = %@",dictString);
return dictString;
}
//将json格式字符串转为字典
-(NSDictionary *)parseJSONStringToNSDictionary{
NSString * JSONString = [self jsonStringFromDict];
//将字符串转成二进制数据
NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
//利用系统自带的JSON解析，解析成字典格式
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
//将字典返回
NSLog(@"responseJSON = %@",responseJSON);
return responseJSON;
}
//去掉非数字字符
-(void)removeUnnumberChar{
NSString * number = @"156-8888-8888";
//invertedset:为翻转
NSCharacterSet *setToRemove = [[ NSCharacterSet characterSetWithCharactersInString:@"0123456789"] invertedSet];
NSArray * numArray = [number componentsSeparatedByCharactersInSet:setToRemove];
NSLog(@"numArray = %@",numArray);
NSString *phoneStr = [numArray componentsJoinedByString:@""];
}
//字符串与int类型互转
-(void)stringToInt{
//数字转字符串
int num = 12;
NSString * intString = [NSString stringWithFormat:@"%d",num];
NSLog(@"intString = %@",intString);
//字符串转数字
NSString * string = @"12";//会转为12；类似@”我“这样的非数字的字符串会转为0
NSInteger stringInt = [string integerValue];
NSLog(@"stringInt = %ld",stringInt);
}
//字符串与data互转
-(void)stringToData{
//把字符串再转变为二进制流
NSString * string = @"I have a dream";
NSData * data=[NSMutableData dataWithData:[string dataUsingEncoding:NSUTF8StringEncoding]];
NSLog(@"data = %@",data);
//二进制流转变为字符串
NSString * dataStr=[[NSMutableString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"dataStr = %@",dataStr);
}
