问题
I might be asking the wrong question here, so I apologize if the answer is on another thread... but I've looked around to no avail.
in a snippet, why doesn't this work?
array = [72,69,76,76,79];
document.write(String.fromCharCode(array));
I'm collecting key events in an array and want to be able to write them out as chars when prompted. And though this works:
document.write(String.fromCharCode(72,69,76,76,79));
I can't seem to get it to work when I pass it along as an array. I've also tried to convert the array toString() first, as well array.join(","); to create a comma separated list ...yet nothing. Any ideas? Is there a better way to convert the values I collect in my array into chars?
回答1:
You could use the function's apply()
method...
document.write(String.fromCharCode.apply(null, array));
jsFiddle.
ES6 can use the spread operator...
document.write(String.fromCharCode(...array));
You could also use the array's reduce()
method, but older IEs do not support it. You could shim it, but the apply()
method is better supported.
document.write(array.reduce(function(str, charIndex) {
return str += String.fromCharCode(charIndex);
}, ''));
jsFiddle.
回答2:
Yes, you can use apply() to call a function which an array passed in as its arguments:
array = [72,69,76,76,79];
document.write(String.fromCharCode.apply(String, array));
回答3:
If you use .apply()
to call the fromCharCode()
function, you can pass it an array that will be converted into arguments for the function like this:
document.write(String.fromCharCode.apply(this, array));
You can see it work here: http://jsfiddle.net/jfriend00/pfLLZ/
回答4:
The method is more meant to be used like this:
document.write(String.fromCharCode(72,69,76,76,79));
You're passing in an array when the method expects multiple parameters as a list.
回答5:
You may have to use a loop as follows
for(var i = 0; i < array.length; i++)
document.write(String.fromCharCode(array[i]));
}
回答6:
Here's 2 ways that I would do it:
var arr=[119,119,119,46,87,72,65,75,46,99,111,109];
document.write(eval('String.fromCharCode('+arr+')'));
document.write('<hr>');
var arr='119,119,119,46,87,72,65,75,46,99,111,109';
document.write(eval('String.fromCharCode('+arr+')'));
回答7:
Here is a function:
var unCharCode = function(x) {
return this["eval"]("String['fromCharCode'](" + x + ")");
};
document.write(unCharCode([ 119, 119, 119, 46, 87, 72, 65, 75, 46, 99, 111, 109 ]));
document.write("<hr>");
document.write(unCharCode("119,119,119,46,87,72,65,75,46,99,111,109"));
来源:https://stackoverflow.com/questions/9936490/can-i-pass-an-array-into-fromcharcode