I needed to upgrade PHP from version 5.6.38 to version 7.3 by the recommendation from WordPress, so tried to find the way can do that on my CentOS 7.5 server.
Followings are the steps I found
STEP 1.Turn on EPEL repo, enter:
sudo yum -y install epel-release
STEP 2. Turn on Remi repo i.e.remi-php73:
sudo yum-config-manager --enable remi-php72
STEP 3. Refresh repository:
sudo yum update
STEP 4. Install php version 7.2, run:
sudo yum install php