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How to convert a string to number in TypeScript?
...rrect typing and will correctly parse simple decimal integer strings like "123", but will behave differently for various other, possibly expected, cases (like "123.45") and corner cases (like null).
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...
Which is faster in Python: x**.5 or math.sqrt(x)?
... (Python 2.5.2, Windows):
$ python -mtimeit -s"from math import sqrt; x = 123" "x**.5"
1000000 loops, best of 3: 0.445 usec per loop
$ python -mtimeit -s"from math import sqrt; x = 123" "sqrt(x)"
1000000 loops, best of 3: 0.574 usec per loop
$ python -mtimeit -s"import math; x = 123" "math.sqrt(x...
How to represent multiple conditions in a shell if statement?
...
Classic technique (escape metacharacters):
if [ \( "$g" -eq 1 -a "$c" = "123" \) -o \( "$g" -eq 2 -a "$c" = "456" \) ]
then echo abc
else echo efg
fi
I've enclosed the references to $g in double quotes; that's good practice, in general. Strictly, the parentheses aren't needed because the preced...
php中json_decode()和json_encode()的使用方法 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...d"] => int(4)
["e"] => int(5)
}
$data='[
{"Name":"a1","Number":"123","Contno":"000","QQNo":""},
{"Name":"a1","Number":"123","Contno":"000","QQNo":""},
{"Name":"a1","Number":"123","Contno":"000","QQNo":""}
]';
echo json_decode($data);
结果为：
Array ( [0] => stdClass Object ( ...
How do I split a string, breaking at a particular character?
...h JavaScript’s String.prototype.split function:
var input = 'john smith~123 Street~Apt 4~New York~NY~12345';
var fields = input.split('~');
var name = fields[0];
var street = fields[1];
// etc.
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...
Can functions be passed as parameters?
...ing.
func value(x int) string {
return fmt.Sprintf("%v", x)
}
// quote123 passes 123 to convert func and returns quoted string.
func quote123(fn convert) string {
return fmt.Sprintf("%q", fn(123))
}
func main() {
var result string
result = value(123)
fmt.Println(result)
//...
How to display pandas DataFrame of floats using a format string for columns?
... pd
pd.options.display.float_format = '${:,.2f}'.format
df = pd.DataFrame([123.4567, 234.5678, 345.6789, 456.7890],
index=['foo','bar','baz','quux'],
columns=['cost'])
print(df)
yields
cost
foo $123.46
bar $234.57
baz $345.68
quux $456.79
but this ...
Linq code to select one item
...e extension methods directly like:
var item = Items.First(i => i.Id == 123);
And if you don't want to throw an error if the list is empty, use FirstOrDefault which returns the default value for the element type (null for reference types):
var item = Items.FirstOrDefault(i => i.Id == 123);
...
Detect if value is number in MySQL
...l1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
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