在 JavaScript 函数中使用多个 else if 语句

Question

I am a beginning programmer and I am creating my first website. I haver a problem with an else if statement in an function in JavaScript. The problem is that my website always seems to go for the first else if answer, even if its not true. this is the function:

 if (600 <= regenid < 614) { var tempcijfer = 1 } else if (gevoelstempc < 0.1) { var tempcijfer = 1 } else if (0.1 < gevoelstempc < 6.5) { var tempcijfer = 2 } else if (6.5 < gevoelstempc < 10.9) { var tempcijfer = 3 } else if (10.9 < gevoelstempc < 12.9) { var tempcijfer = 4 } else if (12.9 < gevoelstempc < 15.9) { var tempcijfer = 5 } else if (15.9 < gevoelstempc < 17.5) { var tempcijfer = 6 } else if (17.5 < gevoelstempc < 19.5) { var tempcijfer = 7 } else if (19.5 < gevoelstempc < 21.1) { var tempcijfer = 8 } else if (21.1 < gevoelstempc < 22.9) { var tempcijfer = 9 } else if (22.9 < gevoelstempc < 25.2) { var tempcijfer = 10 } else if (25.2 < gevoelstempc < 27.9) { var tempcijfer = 9 } else if (27.9 < gevoelstempc < 30.1) { var tempcijfer = 8 } else if (30.1 < gevoelstempc < 32.9) { var tempcijfer = 7 } else if (32.9 < gevoelstempc < 34.9) { var tempcijfer = 6 } else if (34.9 < gevoelstempc < 37.1) { var tempcijfer = 5 } else if (37.1 < gevoelstempc < 39.1) { var tempcijfer = 4 } else if (39.1 < gevoelstempc < 40.5) { var tempcijfer = 3 } else if (40.5 < gevoelstempc < 41.5) { var tempcijfer = 2 } else if (gevoelstempc > 41, 5) { var tempcijfer = 1 }

tempcijfer always seems to become 1 even if gevoelstempc is bigger than 6.5 ) How do I solve this?

Answer 1

You can not use the condition of if statement like that, you must use operators like && ( for AND operator) and ||( for OR operator)

So your code will be like this:

   if ( regenid >= 600 && regenid < 614 ){ var tempcijfer= 1 } 

and the same for the other conditions in your code.

Answer 2

I think you misunderstand how if works. You are putting two operators on the same comparison. I think that what you trying to do with if( 600<=regenid<614 ) is if(600 <= regenid && regenid < 614). The operator && means "and".