how to add html into a js if statement code example

Example 1: javascript how to do else if

if (condition1) {
  //  block of code to be executed if condition1 is true
} else if (condition2) {
  //  block of code to be executed if the condition1 is false and condition2 is true
} else {
  //  block of code to be executed if the condition1 is false and condition2 is false
}

Example 2: javascript how to do if else

if (condition1) {
  //  block of code to be executed if condition1 is true
} else {
  //  block of code to be executed if the condition1 is false
}