Programmatically construct a condition for use in an if() statement

You can do the tests in a loop.

var allOK = true;
for (var i = 1; i <= 100; i++) {
    if (!document.getElementById("div"+i).innerHTML) {
        allOK = false;
        break;
    }
}
if (allOK) {
    console.log("all my divs have content");
}

You could also give all your DIVs a common class, then use a built-in iterator.

var allDivs = document.getElementsByClassName("divClass");
if (Array.from(allDivs).every(div => div.innerHTML)) {
    console.log("all my divs have content");
}