基本数据类型转换成字符串

//1.int类型换换成字符串
        int a = 10;
        NSString * str1 = [NSString stringWithFormat:@"%d",a];
        NSLog(@"str1 %@",str1);
        
        //2.float -> NSString
        float f = 2.4;
        NSString * str3 = [NSString stringWithFormat:@"%.1f",f];
        NSLog(@"str3 %@",str3);
        
        //3.double - >NSstring
        double d = 65.9898;
        NSString * str4 = [NSString stringWithFormat:@"%.4f",d];
        NSLog(@"str4 %@",str4);
        
        //4.char - > NSString
        char c = ‘c‘;
        NSString * str5 = [NSString stringWithFormat:@"%c",c];
        NSLog(@"str5 %@",str5);
        
        //5.NSString -> int
        NSString * str6 = @"1";
        int i1 = [str6 intValue];
        NSLog(@"i1 %d",i1);
        
        //5.NSString -> float
        NSString * str7 = @"9.8";
        float f1 = [str7 floatValue];
        NSLog(@"f1 %.1f",f1);
        
        //6.NSString -> double
        NSString * str8 = @"8.88";
        double d1 = [str8 doubleValue];
        NSLog(@"d1 %.2f",d1);
        
        //注意:当你要把字符串转换成某种基本数据类型的时候,一定要确定你要转化你的数据是正确
        NSString * str9 = @"i386";
        int i2 = [str9 intValue];
        NSLog(@"is %d",i2);
        
        //7.将字符串中的字母转换成大写
        NSString * str10 = @"china";
        NSString * tmpStr1 = [str10 uppercaseString];
        NSLog(@"tmpStr1 %@ str10 %@",tmpStr1,str10);
        
        //8.将字符中的字母转换成小写
        NSString * str11 = @"CHINA";
        NSString * tmpStr2 = [str11 lowercaseString];
        NSLog(@"tmpStr2 %@",tmpStr2);
        
        //9.将首字母大写
        NSString * str12 = @"china";
        NSString * tmpStr3 = [str12 capitalizedString];
        NSLog(@"tmpStr3  %@",tmpStr3);