double是什么意思
double意思为一对,一双;双重地;酷似的人;把...对折;变成两倍;增加一倍。
double可作形容词、副词、动词用。
double(双精度浮点型)是计算机使用的一种资料型别。
比起单精度浮点数(float),double(双精度浮点数)使用64位(8字节)来储存一个浮点数。它可以表示十进制的15或16位有效数字,负值取值范围为-1.7976E+308到-4.94065645841246544E-324,正值取值范围为4.94065645841246544E-324到1.797693E+308一站式出国留学攻略 http://www.offercoming.com
float和double的区别是什么?
double: [ 'd?0?5bl ]
n. 两倍
a. 两倍的,双重的
v. 加倍的,快步走,加倍努力
词形变化:
名词:doubleness 动词过去式:doubled 过去分词:doubled 现在分词:doubling 第三人称单数:doubles
例句与用法:
1. He is my double, though we are not related.
我们两人虽然没有亲缘关系,他却和我长得一模一样。
2. Is the material single width or double width?
这幅料子是单幅的还是双幅的?
3. The egg has a double yolk.
这只蛋双黄。
4. A couch performs a double service.
躺椅可以(坐卧)两用。
5. The boss wants you you'd better get upstairs at the double.
老板叫你--你最好赶紧上楼去,
6. The brothers work in double harness.
哥儿俩一起工作.
7. She's going for the double this year, the Olympics and the World Championship.
今年她要争取奥林匹克赛和世界杯冠军赛的双料冠军.
8. When I saw her and her twin sister I thought I was seeing double.
我看见她们挛生姐妹时还以为我把一个人看成俩了.
英英解释:
名词double:
1. a base hit on which the batter stops safely at second base
同义词:two-base hit, two-bagger, two-baser
2. a stand-in for movie stars to perform dangerous stunts
同义词:stunt man, stunt woman
3. someone who closely resembles a famous person (especially an actor)
同义词:image, look-alike
4. a quantity that is twice as great as another
5. raising the stakes in a card game by a factor of 2
同义词:doubling
动词double:
1. increase twofold
同义词:duplicate
2. hit a two-base hit
3. bend over or curl up, usually with laughter or pain
同义词:double over, double up
4. do double duty; serve two purposes or have two functions
5. bridge: make a demand for (a card or suit)
6. make or do or perform again
同义词:duplicate, reduplicate, repeat, replicate
形容词double:
1. having more than one decidedly dissimilar aspects or qualities-Frederick Harrison
同义词:dual, twofold, two-fold, treble, threefold, three-fold
2. consisting of or involving two parts or components usually in pairs
同义词:dual, duple
3. twice as great or many
同义词:doubled, twofold, two-fold
4. used of flowers having more than the usual number of petals in crowded or overlapping arrangements
5. used of homologous chromosomes associated in pairs in synapsis
同义词:bivalent
6. large enough for two
7. having two meanings with intent to deceive
同义词:forked
副词double:
1. downward and forward
2. two together
3. to double the degree
同义词:doubly, twice
区别:
1、精度不一样,float是单精度,double是双精度;
2、表示小数的范围不一样,double能表示的范围比float大;
3、double在内存中,占8个字节,float在内存中,占4个字节。
float:浮点型数据类型,FLOAT 数据类型用于存储单精度浮点数或双精度浮点数。浮点数使用?IEEE(电气和电子工程师协会)格式。浮点类型的单精度值具有 4 个字节,包括一个符号位、一个 8 位 二进制指数和一个 23 位尾数。由于尾数的高顺序位始终为 1,因此它不是以数字形式存储的。此表示形式为 float 类型提供了一个大约在 -3.4E+38 ~ 3.4E+38 之间的范围。
double:双精度浮点型,此数据类型与单精度数据类型(float)相似,但精确度比float高,编译时所占的内存空间依不同的编译器而有所不同,是double float数据类型,C/C++中表示实型变量的一种变量类型。
扩展资料:
浮点型数据
1、float型
编译系统为每一个float型变量分配4个字节,数值以规范化的二进制数指数形式存放在存储单元中。
2、double型
为了扩大能表示的数值范围,用8个字节存储一个double型数据,可以得到15位有效数字。
3、long double型
不同的编译系统对long double型的处理方法不同,Visual C++6.0对long double型和double一样处理,分配8个字节。
参考资料:
百度百科-float
百度百科-double
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