1if (time < 10) {
2  greeting = "Good morning";
3} else if (time < 20) {
4  greeting = "Good day";
5} else {
6  greeting = "Good evening";
7}

1if (condition1) {
2  //  block of code to be executed if condition1 is true
3 }
4else if (condition2) {
5  //  block of code to be executed if the condition1 is false and 
6  //  condition2 is true
7} else {
8  //  block of code to be executed if the condition1 is false and 
9  //  condition2 is false
10 }

1var age=20;
2if (age < 18) {
3	console.log("underage");
4} else {
5	console.log("let em in!");
6}

1var age=20;
2if (age < 18) {
3	console.log("underage");
4} else {
5	console.log("let em in!");
6}
7