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How do I parse a string into a number with Dart?
...ing into an integer with int.parse(). For example:
var myInt = int.parse('12345');
assert(myInt is int);
print(myInt); // 12345
Note that int.parse() accepts 0x prefixed strings. Otherwise the input is treated as base-10.
You can parse a string into a double with double.parse(). For example:
va...
What is the best Java email address validation method? [closed]
...tor, and "clearly", they are not valid. Here we go: ., .com, com., abc and 123. Also, adding leading or trailing white space do not invalidate the strings either. You be the judge!
– Martin Andersson
Mar 19 '13 at 21:12
...
How to validate phone numbers using regex
...ou should discard the (0) entirely).
Then, you end up with values like:
12345678901
12345678901x1234
345678901x1234
12344678901
12345678901
12345678901
12345678901
+4112345678
+441234567890
Then when you display, reformat to your hearts content. e.g.
1 (234) 567-8901
1 (234) 567-89...
Why does isNaN(“ ”) (string with spaces) equal false?
...
But parseInt("123abcd") returns 123, which means isNaN(parseInt("123abcd")) will return false while it should return true!
– Pawan Nogariya
Dec 27 '12 at 6:23
...
In Python, how do I index a list with another list?
...
A functional approach:
a = [1,"A", 34, -123, "Hello", 12]
b = [0, 2, 5]
from operator import itemgetter
print(list(itemgetter(*b)(a)))
[1, 34, 12]
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impro...
Why would I ever use push_back instead of emplace_back?
... will be invalid after the call.
std::vector<int> v;
v.emplace_back(123);
v.emplace_back(v[0]); // Produces incorrect results in some compilers
On one compiler, v contains the values 123 and 21 instead of the expected 123 and 123. This is due to the fact that the 2nd call to emplace_back re...
How can I print the contents of a hash in Perl?
...
Data::Dumper is your friend.
use Data::Dumper;
my %hash = ('abc' => 123, 'def' => [4,5,6]);
print Dumper(\%hash);
will output
$VAR1 = {
'def' => [
4,
5,
6
],
'abc' => 123
...
What is the difference between parseInt() and Number()?
...
typeof parseInt("123") => number
typeof Number("123") => number
typeof new Number("123") => object (Number primitive wrapper object)
first two will give you better performance as it returns a primitive instead of an object.
...
Fastest sort of fixed length 6 int array
...static int seed = 76521;
while (n--) *a++ = (seed = seed *1812433253 + 12345);
}
#define NTESTS 4096
int main() {
int i;
int d[6*NTESTS];
ran_fill(6*NTESTS, d);
unsigned long long cycles = rdtsc();
for (i = 0; i < 6*NTESTS ; i+=6) {
sort6_fast(d+i);
}
cyc...
How do you round to 1 decimal place in Javascript?
...turn Math.round(value * multiplier) / multiplier;
}
... usage ...
round(12345.6789, 2) // 12345.68
round(12345.6789, 1) // 12345.7
... defaults to round to nearest whole number (precision 0) ...
round(12345.6789) // 12346
... and can be used to round to nearest 10 or 100 etc...
round(12345....