forEach

if (randNum != 3) return;
inputAnswerAll.forEach(
    function(answerText) {
        [
            { text: '寝転', comment: 'いつも寝転んでるよね！' },
            { text: ['落着き', '落ち着'], comment: 'いつも落ち着いてるよね！' },
        ].forEach(
            function(o) {
                var correct = false;
                var text;
                if (typeof o.text !== 'object') {
                    correct = answerText == o.text;
                    text = o.text;
                } else {
                    text = o.text.find(function(t) { return answerText == t; });
                    correct = !!text;
                }
                if (!correct) return;
                correctAnswerEasyQ();
                commentary1.innerText = `答えは、【${text}】`;
                commentary2.innerText = o.comment;
            }
        );
    }
);