php简单的正则表达式搜索和替换和随机子串

Question

i have a string to be used for latex later the string is... roughly

$string  = "\\sin\\left(x\ight)^{2}";

where the sin could also be cos, tan, sec, log, etc.. the exponent could also be any integer, float or variable, the argument could be anything..

I would like a regex function that turns it into

$string  = "\\sin^{2}\\left(x\ight)";

or more generally

generalstring = "f(t)^{n}";

to be turned into "f^{n}(t)"; my apologies in advance, i have a feeling this should be extremely easy to do, I'm just learning this.

oh also i would like to restric this to only strings with trig functions logs and some other ones where my functions are not printing correctly.

Answer 1

Please try the following code:

$string = preg_replace('/\\\\(\w+)\\\\left\\((.+?)\\\ight\\)\\^\\{([^}]+)\\}/','\\\\$1^{$3}\left($2ight)',$string);

For me, the output is:

print "$string
";

\sin^{2}\left(xight)

Another test:

$string  = "\\cos\\left(3x\ight)^{2.6}";

Output:

\cos^{2.6}\left(3xight)

It also works for multiple functions, since preg_replace is global per default.

$string = "\\sin\\left(x\ight)^{3}\\cos\\left(y\ight)^{2}";

\sin^{3}\left(xight)\cos^{2}\left(yight)

Edit: Please note the corrected expression.