Question

我有一个匹配方程式

＆＃13;

function start() {
 
  var str = "10x2+10x+10y100-20y30";
  var match = str.match(/([a-z])=?(\d+)/g);//find the higher value of power only and also print the power value only withput alphapets).i need match like "100"
  
  var text;
  if(match < 10)
    {text = "less 10";}
  else if(match == "10")
    {text == "equal";}
  else
    {text ="above 10";}
  
  document.getElementById('demo').innerHTML=text;
 }
start();

＆＃13;

<p id="demo"></p>

＆＃13;

我需要匹配功率值，并且只能获得更高的功率值。

示例：10x2+10y90+9x91 out --> "90"。我的错误与我的正则表达式相匹配的格式是合适的。谢谢你

Answer 1

变量match包含与正则表达式匹配的所有权力，而不仅仅是一个。你必须迭代它们才能找到最好的。

我接受了你的代码并对其进行了修改以便工作：

function start() {
 
  var str = "10x2+10x+10y100-20y30";
  var match = str.match(/([a-z])=?(\d+)/g);//find the higher value of power only and also print the power value only withput alphapets).i need match like "100"

  var max = 0;
  for (var i = 0; i < match.length; i++) { // Iterate over all matches
    var currentValue = parseInt(match[i].substring(1)); // Get the value of that match, without using the first letter
    if (currentValue > max) {
      max = currentValue; // Update maximum if it is greater than the old one
    } 
  }
  
  document.getElementById('demo').innerHTML=max;
 }
start();

<p id="demo"></p>

Answer 2

试试这个：

const str = '10x2+10x+10y100-20y30'
     ,regex = /([a-z])=?(\d+)/g
const matches = []
let match
while ((match = regex.exec(str)) !== null) {
  matches.push(match[2])
}
const result = matches.reduce((a, b) => Number(a) > Number(b) ? a : b)
console.log(result)

分隔符后的正则表达式匹配并找到更高的匹配数？

2 个答案: