JavaScript

使用老師gitlab程式碼

if

var score = 59;

if (score >= 60)
  console.log("及格");
else
  console.log("不及格");
-->不及格

var score = 61;

if (score >= 60)
  console.log("及格");
else
  console.log("不及格");
-->及格

for

for (var i=1;i<=10;i++) {
    console.log("i=", i);
}
-->
i= 1
i= 2
i= 3
i= 4
i= 5
i= 6
i= 7
i= 8
i= 9
i= 10


for (var i=2; i<=9; i++) {
  for (var j=2; j<=9; j++) {
    console.log(i, '*', j, '=', i*j)
  }
}
-->
2 * 2 = 4
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
2 * 6 = 12
2 * 7 = 14
2 * 8 = 16
2 * 9 = 18
3 * 2 = 6
3 * 3 = 9
3 * 4 = 12
3 * 5 = 15
3 * 6 = 18
3 * 7 = 21
3 * 8 = 24
3 * 9 = 27
4 * 2 = 8
4 * 3 = 12
4 * 4 = 16
4 * 5 = 20
4 * 6 = 24
4 * 7 = 28
4 * 8 = 32
4 * 9 = 36
5 * 2 = 10
5 * 3 = 15
5 * 4 = 20
5 * 5 = 25
5 * 6 = 30
5 * 7 = 35
5 * 8 = 40
5 * 9 = 45
6 * 2 = 12
6 * 3 = 18
6 * 4 = 24
6 * 5 = 30
6 * 6 = 36
6 * 7 = 42
6 * 8 = 48
6 * 9 = 54
7 * 2 = 14
7 * 3 = 21
7 * 4 = 28
7 * 5 = 35
7 * 6 = 42
7 * 7 = 49
7 * 8 = 56
7 * 9 = 63
8 * 2 = 16
8 * 3 = 24
8 * 4 = 32
8 * 5 = 40
8 * 6 = 48
8 * 7 = 56
8 * 8 = 64
8 * 9 = 72
9 * 2 = 18
9 * 3 = 27
9 * 4 = 36
9 * 5 = 45
9 * 6 = 54
9 * 7 = 63
9 * 8 = 72
9 * 9 = 81

break continue (for)

for (var i=1;i<=10;i++) {
    if (i == 3) continue;
    if (i == 8) break;
    console.log("i="+i);
}
-->
i=1
i=2
i=4
i=5
i=6
i=7
of(for)
var a=[1,6,2,5,3,6,1];

for (var o of a) {
  console.log("o=", o);
}
-->
o= 1
o= 6
o= 2
o= 5
o= 3
o= 6
o= 1
each(for)
var a=[1,6,2,5,3,6,1];

for (var i in a) {
  console.log("a[%s]=%d", i, a[i]);
}
-->
a[0]=1
a[1]=6
a[2]=2
a[3]=5
a[4]=3
a[5]=6
a[6]=1

while

var i=1;
while (i<=10) {
  console.log("i=", i);
  i = i + 1;
}
-->
i= 1
i= 2
i= 3
i= 4
i= 5
i= 6
i= 7
i= 8
i= 9
i= 10
sum(while)
var sum=0;
var i=1;
while (i<=10) {
  sum = sum + i;
  console.log("i=", i, " sum=", sum);
  i = i + 1;
}
-->
i= 1  sum= 1
i= 2  sum= 3
i= 3  sum= 6
i= 4  sum= 10
i= 5  sum= 15
i= 6  sum= 21
i= 7  sum= 28
i= 8  sum= 36
i= 9  sum= 45
i= 10  sum= 55