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When NOT to call super() method when overriding?
...ustom class, I extend its native class. Then when I want to override the base method, I always call super() method, just like I always do in onCreate , onStop , etc.
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Why does PHP 5.2+ disallow abstract static class methods?
After enabling strict warnings in PHP 5.2, I saw a load of strict standards warnings from a project that was originally written without strict warnings:
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Adding a column to a data.frame
I have the data.frame below. I want to add a column that classifies my data according to column 1 ( h_no ) in that way that the first series of h_no 1,2,3,4 is class 1, the second series of h_no (1 to 7) is class 2 etc. such as indicated in the last column.
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Combine two or more columns in a dataframe into a new column with a new name
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Use paste.
df$x <- paste(df$n,df$s)
df
# n s b x
# 1 2 aa TRUE 2 aa
# 2 3 bb FALSE 3 bb
# 3 5 cc TRUE 5 cc
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assign multiple variables to the same value in Javascript
I have initialized several variables in the global scope in a JavaScript file:
5 Answers
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Call a function from another file?
...te from file import function, and then call the function using function(a, b). The reason why this may not work, is because file is one of Python's core modules, so I suggest you change the name of your file.
Note that if you're trying to import functions from a.py to a file called b.py, you will n...
Android微信智能心跳方案 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...心跳就可以很大程度的保证下一次心跳环境是正常的。
b）成功一次认定，失败连续累积认定：成功是绝对的，连续失败多次才可能是失败。
c）临界值避免：我们使用比计算出的心跳稍微小一点的值做为稳定心跳避免临界值。...
Assign pandas dataframe column dtypes
... I've had to manually parse into a list of lists, as the file was not amenable for pd.read_csv )
6 Answers
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O(nlogn) Algorithm - Find three evenly spaced ones within binary string
...thms test yesterday, and I can't figure out the answer. It is driving me absolutely crazy, because it was worth about 40 points. I figure that most of the class didn't solve it correctly, because I haven't come up with a solution in the past 24 hours.
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Creating a “logical exclusive or” operator in Java
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Java does have a logical XOR operator, it is ^ (as in a ^ b).
Apart from that, you can't define new operators in Java.
Edit: Here's an example:
public static void main(String[] args) {
boolean[] all = { false, true };
for (boolean a : all) {
for (boolean b: all) ...