//创建一个空字符串
NSString *str2 = [[NSString alloc]init];
NSString *str3 = [NSString string];
NSLog(@"str2 = %@",str2);
NSLog(@"str3 = %@",str3);
//快速创建一个字符串
NSString *str4 = [[NSString alloc]initWithString:str1];
NSString *str5 = [NSString stringWithString:str1];
NSLog(@"str4 = %@",str4);
NSLog(@"str5 = %@",str5);
//创建一个格式化字符串
NSString *str6 = [[NSString alloc]initWithFormat:@"%d",10];
NSString *str7 = [NSString stringWithFormat:@"%.2f",10.8099887];
NSLog(@"str6 = %@",str6);
NSLog(@"str7 = %@",str7); |
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