javascript语句
一:条件语句
1.if...else
栗子:
<script>
var i=1;
if(i==1){
alert("good");
}
else{
alert("sad");
}
</script>
2.switch
栗子:判断成绩所属等级
<script>
var i=90;
var grade;
var score=parseInt(i/10);
switch(score){
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
grade="不及格,还需加油";
alert(grade);
break;
case 6:
grade="及格,继续努力";
alert(grade);
break;
case 7:
case 8:
grade="优秀";
alert(grade);
break;
case 9:
case 10:
grade="非常棒";
alert(grade);
break;
default:
grade="你要上天吗?"
alert(grade);
}
</script>
二:循环语句
1.for循环 输出1-10
for(i=1;i<=10;i++){
document.write(i+"<br/>");
}
2.while循环 输出1-10
var i=1;
while(i<=10){
document.write(i+"<br>");
i++;
}
3.do...while循环 输出1-10
var i=1;
do{
document.write(i+"<br/>");
i++;
}
while(i<=10);