tryjsref_indexof 在线代码实例

 <p id="demo">Click the button to locate where in the string a specifed value occurs.</p>

<button onclick="myFunction()">Try it</button>

<script>
function myFunction()
{
var str="Hello world, welcome to the universe.";
var n=str.indexOf("welcome");
document.getElementById("demo").innerHTML=n;
}
</script>