numbers

Objective-C: Numbers only text field? [duplicate]

南笙酒味 提交于 2020-01-01 04:01:23
问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: Iphone UITextField only integer I want to place a text field that only accepts numbers (0-9, doesn't even need decimals), but even using the "Number Pad" entry option I still get a keyboard with various symbols on it. Is there a better control for this, is there a better control for what I'm doing, or do I just have to validate input manually? 回答1: The following code will allow you to only input numbers as well

python中列表的常用方法

廉价感情. 提交于 2019-12-31 22:37:53
列表中的方法 # 列表方法 ''' 1. append:在列表最后插入新的值 2. clear:用于清除列表的内容 3. copy:用于复制一个列表 //通过分片也是可以复制一个列表的 4. count:用于统计某个元素在列表中出现的次数 5. extend:用于在列表结尾插入另一个列表,也就是让两个列表首尾相接。 该方法改变的是被扩展的列表。 list1.extend(list2)//这一步是 把list2接到list1的后面 他改变的是list1的本身 比如list1长度为3 list2长度为4 那么我们调用这个方法后 list1的长度 就变成了7 改变了list1的长度 ,而我们之前讲过的 列表的相加创建一个新的列表 和extend 这个方法 是本质的区别 6. index:用于从列表中找出某个值第一次出现的索引位置 7. insert:用于将值插入到列表中的指定位置 //这个方法可以取代append 因为可以在列表中的任意位置插入 8. pop:用于移除弹出列表中的元素(默认是最后一个元素),并返回该元素的值 9. remove:用于移除列表中某个值的第一次匹配项 10. reverse:用于将列表中的元素反向存放 11. sort:用于对列表进行排序,调用该方法会改变原来的列表 ''' from sqlalchemy.sql.expression import false

Why aren't rational numbers implemented and stored as fractions with zero loss of information? [closed]

随声附和 提交于 2019-12-31 11:33:07
问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . I know this is a bit hypothetical but I am wondering why no language I know does it. For example, you want to store 1/3. Give the

Why aren't rational numbers implemented and stored as fractions with zero loss of information? [closed]

时光总嘲笑我的痴心妄想 提交于 2019-12-31 11:32:25
问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . I know this is a bit hypothetical but I am wondering why no language I know does it. For example, you want to store 1/3. Give the

What does passing an integer number as the argument for `toString` do?

久未见 提交于 2019-12-31 07:47:07
问题 I'm taking a course on JavaScript but have no guide on toString method, what's the purpose of these two outputs in JavaScript: (35).toString(36) >>> "z" !!! (35).toString(37) >>> throws a RangeError !!! I am utterly confused as to why I am getting these results, I would really appreciate it if someone could shed some light on this. 回答1: tldr: Number.prototype.toString can take an argument called radix that specifies the numeric base to use for the string representation of the number in

Want to create serial numbers

别来无恙 提交于 2019-12-31 05:22:23
问题 I want to generate the serial no.s e.g. I have, NID ----- ABD90 BGJ89 HSA76 and I want, ID NID --------- 1 ABD90 2 BGJ89 3 HSA76 What code should I run for this outcome? Please help me. 回答1: Since you tagged SAS, I'll answer with SAS. Based on your question, getting that result from that input would be as simple as this data result; ID=_N_; set input; run; or proc sql; select ID as monotonic() ,NID from input ; quit; In pure Oracle you would do this select rownum, NID from input However you

Create leading zero in Oracle

时间秒杀一切 提交于 2019-12-31 02:59:06
问题 I am using Adempiere which has database Oracle I have window called Stock Code from table called M_StockCode The fields are Code and Description . Currently, Code data type is Number and Description is Varchar2 I want to input Sparepart with Code 01 , and Body Repair with Code 02 . As I input the data in Adempiere and save it, what will show is Sparepart with Code 1 (without leading zero) I've tried putting LPAD function but it's still failed. How can I put 01 both in Adempiere interface and

Convert numbers to words with VBA

99封情书 提交于 2019-12-31 02:32:08
问题 I have a column of numbers. In the next column, I want the text/word conversion of the numbers. Example : 123.561 would convert to One hundred twenty three point five six one . I do not want to convert to currency, just number to text, with any number of decimal places. How can I do this? 回答1: Edit: I've adapted the procedure below to non-currency, unlimited decimal places. Edit 2 considers internationalisation via two changes in (1) Function SpellNumber and (2) Function fractionWords to make

Check if variable is number: Applescript

别说谁变了你拦得住时间么 提交于 2019-12-31 01:54:11
问题 How can I check if a variable is a number? I'm trying this: set a to 5 if a is a number display dialog "Yes! It's a number!" end if I've also tried this code: set a to 5 if a is integer display dialog "Yes! It's a number!" end if But unfortunately it doesn't work as expected. 回答1: class of a is integer will fail if you use set a to "5" This will work if even if the variable is a number but was entered as text. set a to "5" try set a to a as number display dialog "Yes! It's a number!" end try

Choose specific number with probability

社会主义新天地 提交于 2019-12-30 18:22:06
问题 How can one choose a number with a specific probability p ? Say we must choose between {0, 1} and the probability p stands for choosing 1 . So when p=0.8 we choose 1 with 80% and 0 with 20%. Is there a simple solution in R for this? 回答1: Take a look at sample function. > set.seed(1) > sample(c(0,1), size=10, replace=TRUE, prob=c(0.2,0.8)) [1] 1 1 1 0 1 0 0 1 1 1 From the helpfile you can read: sample takes a sample of the specified size from the elements of x using either with or without