The subtraction operator (-
) subtracts numbers.
var a = 9;
var b = 3;
var c = a - b;
c
will now be 6
If a string or boolean is provided in place of a number value, it gets converted to a number before the difference is calculated (0
for false
, 1
for true
):
"5" - 1; // 4
7 - "3"; // 4
"5" - true; // 4
If the string value cannot be converted into a Number, the result will be NaN
:
"foo" - 1; // NaN
100 - "bar"; // NaN