The plus + exists in two forms: the binary form that we used above and the unary form.
The unary plus or, in other words, the plus operator + applied to a single value, doesn’t do anything to numbers. But if the operand is not a number, the unary plus converts it into a number.
// No effect on numbers
let x = 1;
alert( +x ); // 1
let y = -2;
alert( +y ); // -2
// Converts non-numbers
alert( +true ); // 1
alert( +"" ); // 0