$\because a$、$b$互为倒数，$c$、$d$互为相反数，$m$的绝对值是$1$，
$\therefore c+d=0$，$ab=1$，$|m|=1$，
$\therefore m=\pm 1$，
则$2ab-\left(c+d\right)+m=2\times 1+0+\left(\pm 1\right)=3$或$1$.

$\because a$、$b$互为倒数，$c$、$d$互为相反数，$m$的绝对值是$1$，
$\therefore c+d=0$，$ab=1$，$|m|=1$，
$\therefore m=\pm 1$，
则$2ab-\left(c+d\right)+m=2\times 1+0+\left(\pm 1\right)=3$或$1$.