字符串操作
// main.m
// String
//
// Created by huanghaiyan on 14-10-7.
// Copyright (c) 2014年 huanghaiyan. All rights reserved.
#import <Foundation/Foundation.h>
#include <string.h>
int main(int argc,const char * argv[])
{
//字符串操作
NSString *string = @"hello,world!";
NSLog(@"%@",string);
NSString *formatStr = [NSStringstringWithFormat:@"I am zhang%@, I am %d years old!",@"san",15];
NSLog(@"%@",formatStr);
NSString *formatStr1 = [NSStringstringWithFormat:@"I am zhang%d, I am %d years old!",3,15];
NSLog(@"%@",formatStr1);
//通过C字符串来创建OC的字符串
NSString *formCStr = [NSStringstringWithCString:"hello,world"encoding:NSUTF8StringEncoding];
NSLog(@"formCStr:%@",formCStr);
//将OC的字符串对象转换成C的字符串
const char *ptr = [formCStrUTF8String];
printf("===>%s\n",ptr);
//获取字符串长度
NSUInteger length = [formatStr length];
NSLog(@"formatStr's length is :%lu",length);
//c语言字符串比较
char *str ="hello,world!";
char arr[] = "Hello,world!";
if(strcasecmp(str, arr) ==0)
{
NSLog(@"str is equal to arr");
}else{
NSLog(@"str is not equal arr");
}
//oc 字符串比较
NSString *string1 =@"This is String1";
NSString *string2 =@"This is string2";
BOOL result01 = [string1 isEqualToString:string2];
NSLog(@"result01 :%d",result01);
//compare (返回三种值)
NSComparisonResult result02 = [string1 compare:string2];
NSLog(@"result02 :%ld",result02);//结果为-1表示左值比右值小
//不区分大小写比较1
if([string1caseInsensitiveCompare:string2] == NSOrderedSame){
NSLog(@"string1 is equal to string2");
}else {
NSLog(@"not equal");
}
//不区分大小写比较2
NSComparisonResult result03 = [string1compare:string2 options:NSCaseInsensitiveSearch |NSNumericSearch];
if (result03 == NSOrderedSame) {
NSLog(@"string1 is equal to string2");
}elseif(result03 == NSOrderedSame){
NSLog(@"string1 is little!");
}else{
NSLog(@"string2 is little!");
}
//改变字符串的大小写
NSString *string3 = @"Astring";
NSString *string4 = @"String";
NSLog(@"after uppercase string3:%@",[string3uppercaseString]);
NSLog(@"after lowercase string4:%@",[string4lowercaseString]);
//字符串是否含有后缀
NSString *filename = @"chaper.txt";
if([filename hasSuffix:@".txt"])
{
NSLog(@"It's a txt file");
}
//字符串是否含有前缀
NSString *fileName2 =@"draft-hello.pages";
if([fileName2 hasPrefix:@"draft"])
{
NSLog(@"It's a draft");
}
//取出指定字符串中子串的范围
NSString *string5 =@"hello world,hello kitty!";
NSString *string6 = @"kitty";
NSRange range = [string5 rangeOfString:string6];
NSString *rangeStr = [NSStringstringWithFormat:@"Location is %lu,length is %lu",range.location,range.length];
NSLog(@"range:%@",rangeStr);
//提取子串(子串从哪个位置开始到最后)
NSString *string7 =@"This is a string";
NSString *string8 = [string7 substringFromIndex:3]//截取string7从3开始到最后
//截取string7的后四位
NSString *string8 = [string7 substringFromIndex:string7 - 4];
NSLog(@"string8:%@",string8);
//提取子串(从开始到指定的位置)
NSString *string9 = [string7 substringToIndex:3];
NSLog(@"string9:%@",string9);
//提取子串(从哪个位置开始，提取多长个字符串)
NSString *string10 = [string7 substringWithRange:NSMakeRange(3,6)];
NSLog(@"string10:%@",string10);
NSString *string11 = [string7 substringWithRange:NSMakeRange(3,0)];
NSLog(@"string10:%@",string11);
//文件扩展名
NSString *fileName3 = @"~/hello.txt";
NSLog(@"Extention:%@",[fileName3pathExtension]);
//绝对路径和相对路径的转换
NSString *path = @"~/test.mou";
NSString *absPath = [pathstringByExpandingTildeInPath];
NSLog(@"absPath:%@",absPath);
NSLog(@"path:%@",[absPathstringByAbbreviatingWithTildeInPath]);
return 0;
}