// // main.m // NSString_Demo2 // // Created by dancer on 14/11/18. // Copyright (c) 2014年 dancer. All rights reserved. //
#import
int main(int argc, const char * argv[]) {
@autoreleasepool { // NSString 的常用方法 // 1.字符串对象的创建 NSString* str = @"beijing"; NSString* str1 = [[NSString alloc] initWithFormat:@"beijing %d",1949]; NSString* str2 = [[NSString alloc] initWithString:str]; const char* p = "beijing I love you"; NSString* str3 = [[NSString alloc] initWithUTF8String:p]; const char* p1 = [str3 UTF8String]; NSString* cStr1 = [NSString stringWithFormat:@"beijing %d",1949]; NSString* cStr2 = [NSString stringWithString:cStr1]; NSString* cStr3 = [NSString stringWithUTF8String:p]; // 2.字符串对象的操作方法 // 求长度 int length = (int)[cStr1 length]; NSLog(@"length = %d",length); // 指定索引求字符 char ch = [cStr1 characterAtIndex:0]; // 提取子串 NSString* subStr = [cStr1 substringFromIndex:4]; subStr = [cStr1 substringToIndex:4]; subStr = [cStr1 substringWithRange:NSMakeRange(2, 3)]; // NSRange转换成NSString NSRange newRange = NSMakeRange(2, 3); NSString* rangeStr = NSStringFromRange(newRange); // 数字串转换成数字 NSString* numStr = @"123.45"; float num1 = [numStr floatValue]; int num2 = [numStr intValue]; // 字符串对象的比较方法 NSString* kStr1 = @"beijing"; NSString* kStr2 = @"shanghai"; if ([kStr1 isEqualToString:kStr2]) { NSLog(@"kStr1 = kStr2"); } // compare方法,比较两个字符串对象的大小 NSComparisonResult result = [kStr1 compare:kStr2]; if (result == NSOrderedAscending) { NSLog(@"kStr1 < kStr2"); }else if (result == NSOrderedDescending){ NSLog(@"kStr1 > kStr2"); }else NSLog(@"kStr1 = kStr2");
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