RegEx使用php替换字符串结尾

Question

I try to read chemical formulas like C6H12-1, C6H12-1(co2) using

"/(?i)\b[a-z]+(?:\d+[a-z]+)*\b/"

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$fuel_value = preg_replace("/(?i)\b[a-z]+(?:\d+[a-z]+)*\b/","",$fuel);
print_r(implode($fuel_value));

It prints C6-H5(CH3) 15.0 ! ( ) as output, but i only want to read C6-H5(CH3) how can i eliminate data after space ie 15.0 ! ( )

I tried to use $ but i failed. I am working on php for first time.

Apologize if my question is silly

Answer 1

I would use this:

FUEL ([\w\(\)-]+)

Here's a demo .

Answer 2

i use preg_match_all instead of preg_replace and list chemical formula's

$str = "FUEL C6H12-1 0.0 ! Fuel Fraction oFUEL C6H12-1 0.0 ! Fuel Fraction of Total Fuel Species(molefr) FUEL C6H5CH3 15.0 ! Fuel Fraction of Total Fuel Species(molefr) FUEL IC8H18 72.5 ! Fuel Fraction of Total Fuel Species(molefr) FUEL NC7H16 12.5 ! Fuel Fraction of Total Fuel Species (molefr) FUEL T124MBZ 0.0 ! Fuel Fraction of Total Fuel Species (molefr)";

preg_match_all("/[A-Z]+\d.*?[\s]/",$str,$match);

print_r($match);