programming languages - if/else and if/elseif

Question

If I have a statement block like this:

if (/*condition here*/){ }
else{ }

or like this:

if (/*condition here*/)
else if (/*condition here*/) {}
else if (/*condition here*/) {}

What is the difference?

It seems that with if/else, if part is for true state and the else part is for all other possible options (false). An else-if would be useful for a number of conditions. This is my understanding, is there anything more I should be aware of?

Answer 1

Without "elseif" syntax you would have to write chain if-statements for processing one of several possible outcomes this way:

if( str == "string1" ) {
   //handle first case
} else {
    if( str == "string2" ) {
       //handle second case
    } else {
       if( str == "string3" ) {
           //handle third case
       } else {
          //default case
       }
    }
 }

instead you can write

if( str == "string1" ) {
   //handle first case
} else if( str == "string2" ) {
   //handle second case
} else if( str == "string3" ) {
   //handle third case
} else {
   //default case
}

which is completely the same as the previous one, but looks much nicer and is much easier to read.