JavaScript Q1

JS(1)

<script>
for(var i = 1; i <= 3; i++){
	alert(i);
}
</script>

JS(2)

<script>
var number ;

number = prompt('数字を入力して下さい','半角英数字で入力して下さい');
number = parseInt(number);

number >= 70 ? document.write('合格です') : document.write('不合格です');
</script>

JS(3)

<script>
var random = Math.random();

if(random < 0.21){
	document.write('<p>','今日はラッキーデー！','</p>');
}else if(random<0.85){
	document.write('<p>','ボチボチ頑張っていきましょう〜','</p>');
}else{
	document.write('<p>','思わぬ落とし穴にご注意を…','</p>');
}
</script>

JS(4)

<script>
var today;
var hour;
today= new Date();
hour = today.getHours();

if(hour<6){
	document.images['pic'].src='img/midnight.jpg';
}else if(hour<9){
	document.images['pic'].src='img/morning.jpg';
}else if(hour<14){
	document.images['pic'].src='img/afternoon.jpg';
}else if(hour<18){
	document.images['pic'].src='img/evening.jpg';
}else{
	document.images['pic'].src='img/night.jpg';
}
</script>