如果在Javascript中不起作用

Question

The If always gives me the last result

check this snippet

 function calc(on, ep, am, ek, b1, b2, b3, b4) { var sum, mo; b1 = parseInt(b1); b2 = parseInt(b2); b3 = parseInt(b3); b4 = parseInt(b4); sum = b1 + b2 + b3 + b4; mo = sum / 4; if (mo < 5) { x = "Not Good"; } if (mo < 6, 5 && mo > 4, 99) { x = "Good"; } if (mo < 8, 5 && mo > 6, 49) { x = "Really Good"; } if (mo > 8, 49) { x = "Perfect"; } alert("O " + on + " " + ep + " " + am + " who is in " + ek + "th semester had avereged " + mo + " " + x); } 

I cant get it to work with else if or something like that but I need it to work however it is

Answer 1

JavaScript floating point literals use a . character (U+002E : FULL STOP) as a decimal point, not a , character (U+002C : COMMA) (which is a comma operator ).

Answer 2

As already said you have to use . and not , . Your mo < 6,5 && mo > 4,99 will always evaluate to 99 which is truthy. So it does not matter what value the mo has.

 var mo = 10; console.log( (mo < 6,5 && mo > 4,99) ); 

See MDN: Comma operator for more informations:

The comma operator evaluates each of its operands (from left to right) and returns the value of the last operand.