The construction else if is
simultaneously the
else
statement and the following
if
condition.
Syntax
if (logical expression 1) {
/*
a code located here will be executed
if the logical expression 1 is true
*/
} else if (logical expression 2) {
/*
a code located here will be executed
if the logical expression 2 is true
*/
} else {
/*
a code located here will be executed
if the logical expression 2 is false
*/
};
If there is only one expression in curly braces, these curly braces can be omitted.
Example
Let's check whether the number
1, 2 or 3
is stored in the variable and
display the corresponding value:
let num = 1;
if (num == 1) {
alert('value1');
} else if (num == 2) {
alert('value2');
} else if (num == 3) {
alert('value3');
} else {
alert('unknown value');
};