如何从变量中删除所有非数字字符

Question

如何从javascript变量中删除所有文本字符（不是数字或浮点数）？

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作为号码。 parseInt正在给出NaN结果。

Answer 1

您可以替换非数字

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

或者您可以匹配号码

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

比赛也可能更具体

Answer 2

使用如下正则表达式：

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);

试试这个小提琴