​x
 
<!DOCTYPE html>
<html>
<body>
​
<p>单击按钮可解析不同的字符串。</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
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<script>
function myFunction() {
  var a = parseFloat("10")
  var b = parseFloat("10.00")
  var c = parseFloat("10.33")
  var d = parseFloat("34 45 66")
  var e = parseFloat("   60   ")
  var f = parseFloat("40 years")
  var g = parseFloat("He was 40")
​
  document.getElementById("demo").innerHTML =
  a + "<br>" +
  b + "<br>" +
  c + "<br>" +
  d + "<br>" +
  e + "<br>" +
  f + "<br>" +
  g;
}
</script>
​
</body>
</html>
​