elif exist in js 3f

1x = 10;
2if(x > 100 ) console.log('over 100')
3else if (x > 90 ) console.log('over 90')
4else if (x > 50 ) console.log('over 50')
5else if (x > 9 ) console.log('over 9')
6else console.log('lower 9') 
7

1if (condition) {
2    ...
3} else {
4    if (condition) {
5        ...
6    } else {
7        ...
8    }
9}
10

1if(condition)
2{
3
4} 
5else if(condition)
6{
7
8}
9else
10{
11
12}
13

1if (condition) {
2
3} else if (other_condition) {
4
5} else {
6
7}
8

1if (...) {
2
3} else if (...) {
4
5} else {
6
7}
8

1if ( 100 < 500 ) {
2   //any action
3}
4else if ( 100 > 500 ){
5   //any another action
6}
7

1switch (true) {
2  case condition1:
3     //e.g. if (condition1 === true)
4     break;
5  case condition2:
6     //e.g. elseif (condition2 === true)
7     break;
8  default:
9     //e.g. else
10}
11

1if (condition) {
2
3} else {
4
5   if (other_condition) {
6
7   } else {
8
9   }
10
11}
12