如何從變量中刪除所有非數字字符

Question

如何從javascript變量中刪除所有文本字符（不是數字或浮點數）？

function deduct(){
    var getamt= document.getElementById('cf').value; //eg: "Amount is 1000"
    var value1 = 100;
    var getamt2 = (value1-getamt);
    document.getElementById('rf').value=getamt2;
}

我要用getamt作為號碼。 parseInt正在給出NaN結果。

Answer 1

您可以替換非數字

  var str = "Amount is 1000"; var num = +str.replace(/[^0-9.]/g,""); console.log(num); 

或者您可以匹配號碼

  var str = "Amount is 1000"; var match = str.match(/([0-9.])+/,""); var num = match ? +match[0] : 0; console.log(num); 

比賽也可能更具體

Answer 2

使用如下正則表達式：

var getamt= document.getElementById('cf').value; //eg: Amount is 1000
var value1 = 100;
var getamt2 = value1 - getamt.replace( /\D+/g, ''); // this replaces all non-number characters in the string with nothing.
console.log(getamt2);

試試這個小提琴