NSString代表字符序列不可变的字符串，功能更强大，更方便简单。
下面代码列举了大部分常用的NSString方法。
//
// main.m
// OcString
//
// Created by mac on 14-12-2.
// Copyright (c) 2014年
mac. All rights reserved.
//
#import
<Foundation/Foundation.h>
void dynamicCreateString()
{
//1
NSString *str1 =
@"neusoft i love you";
NSLog(@"%@",str1);
//2
NSString *str2 = [[NSString
alloc]init];
[str2 release];
//使用oc字符串付初值
NSString *str3 = [[NSString
alloc]initWithString:str1];
NSLog(@"%@",str3);
[str3 release];
//使用c语言的字符串初始化
NSString *str4 = [[NSString
alloc]
initWithUTF8String:"I love you"];
NSLog(@"%@",str4);
[str4 release];
//格式化创建方式
NSString *str5 = [[NSString
alloc]initWithFormat:@"i
am %i years old",10];
NSLog(@"%p, %@",str5,str5);
//[str5 release];
NSString *str6 = [str5
stringByAppendingString:str1];
NSLog(@"%p, %@",str6,str6);
[str5 release];
[str6 release];
//使用文件初始化
NSError * error;
NSString *str7 = [[NSString
alloc]initWithContentsOfFile:@"/Users/mac/Desktop/a.txt"
encoding:NSUTF8StringEncoding
error:&error];
NSLog(@"%@, %@",str7,error);
NSString * path =
@"file:///Users/mac/Desktop/a.txt";
NSString * httpContents =
@"http://people.com.cn";
NSURL * url = [NSURL
URLWithString:httpContents];
NSString *str8 = [[NSString alloc]initWithContentsOfURL:url encoding:CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000)
error:&error];
NSLog(@"%@, %@",str8,error);
[str8 release];
}
void staticCreateString()
{
NSString * str1 = [NSString
stringWithFormat:@"i am %i years old",10];
NSLog(@"%@",str1);
}
#pragma mark
导出到文件中
void export()
{
//向文件中写入，持久化的过程
NSString * str =
@"i was a child , i have a dreamer ";
NSString * path =
@"file:///Users/mac/Desktop/a.txt";
NSError *error;
[str writeToFile:path
atomically:YES
encoding:NSUTF8StringEncoding
error:&error];
NSLog(@"%@",error);
NSURL * url = [NSURL
URLWithString:path];
[str writeToURL:url
atomically:
YES
encoding:NSUTF8StringEncoding
error:&error];
NSLog(@"%@",error);
}
void otherMethord()
{
//请求字符串长度
NSLog(@"%lu",[@"abcd吴剑光"
length]);
NSLog(@"%c",[@"abcd吴剑光"
characterAtIndex:3]);
}
void caseMethord()
{
NSString * str =
@"I‘am boY ,i have a dream";
NSLog(@"%@",[str
uppercaseString]);
NSLog(@"%@",[str
lowercaseString]);
NSLog(@"%@",[str
capitalizedString]);
}
void campareWithString()
{
NSString * str =
@"Z‘am boY ,i have a dream";
NSString * str1 =
@"I‘am boY ,i have a dream";
if ([str
isEqualToString:str1]) {
NSLog(@"true");
}
NSLog(@"%li",[str
compare:str1]);
}
void searchString()
{
NSString * str =
@"neuZ‘am boY ,i have a dream";
NSLog(@"%i",[str
hasPrefix:@"neu"]);
NSLog(@"%i",[str
hasSuffix:@"exm"]);
NSRange range1 = [str
rangeOfString:@"have"];
NSLog(@"%lu,%lu",range1.location,range1.length);
NSRange range2 = [str
rangeOfString:@"have"
options:NSBackwardsSearch];
NSLog(@"%lu,%lu",range2.location,range2.length);
}
void subString()
{
NSString * str =
@"neuZ‘am #boY #i have# a dream";
NSLog(@"%@",
[str substringFromIndex:3]);
NSLog(@"%@",
[str substringToIndex:3]);
NSLog(@"%@",
[str substringWithRange:NSMakeRange(3,
5)]);
NSArray * array = [str
componentsSeparatedByString:@"#"];
NSLog(@"%@",array);
}
void pathString()
{
NSString * str =
@"neuZ‘am #boY #i have# a dream";
NSArray * array = [str
componentsSeparatedByString:@"#"];
NSLog(@"%@",
[NSString
pathWithComponents:array]);
NSString * path =
@"Users/mac/desktop";
NSLog(@"%@",
[path pathComponents]);
NSLog(@"%i",
[path isAbsolutePath]);
NSLog(@"%@",
[path stringByAppendingPathComponent:@"abc"]);
NSLog(@"%@",
path);
}
void extentionString()
{
NSString * path =
@"/Users/mac/Desktop/a.txt";
NSLog(@"%@",
[path pathExtension]);
NSLog(@"%@",
[path stringByDeletingPathExtension]);
NSLog(@"%@",
[path stringByAppendingPathExtension:@"xml"]);
}
void exchangeType()
{
NSString *str1 =
@"234.2342424";
NSString *str2 =
@"234.45";
NSString *str3 =
@"234";
NSString *str4 =
@"abcde";
NSLog(@"%f",[str1
doubleValue]);
NSLog(@"%f",[str2
floatValue]);
NSLog(@"%i",[str3
intValue]);
NSLog(@"%s",[str4
UTF8String]);
}
#pragma mark NSMutableString
void mutableStringOperation()
{
NSMutableString * str = [NSMutableString
stringWithCapacity:10];
[str setString:@"i was girl"];
NSLog(@"%@",
str);
[str appendFormat:@" %i years old",
10];
NSLog(@"%@",
str);
[str replaceCharactersInRange:NSMakeRange(2,
3)
withString:@"abcdekfslfj"];
NSLog(@"%@",
str);
}
int main(int
argc, const
char * argv[]) {
@autoreleasepool {
mutableStringOperation();
exchangeType();
extentionString();
pathString();
subString();
searchString();
dynamicCreateString();
staticCreateString();
export() ;
otherMethord();
caseMethord();
campareWithString();
}
return
0;
}