javascript - 如何验证用户输入？

Question

如果最后输入的数字后面有空格，程序就会中断。如果输入空格，如何阻止函数中断？我尝试了 $.trim 但不知道如何让它工作。还尝试了 if/else 语句

function calculate() {
    var numInput = document.getElementById("qty").value;
    var numArray = numInput.split(" ").map(function(t) {
        return parseInt(t);
    });

    var minValue = Math.min.apply(null, numArray);
    var maxValue = Math.max.apply(null, numArray);
    var sumValue = numArray.reduce(function(previous, current) { return previous + current });
    var productValue = numArray.reduce(function(previous, current) { return    previous * current });
    var meanValue = numArray.reduce(function(previous, current) { return previous + current / numArray.length });

    document.getElementById("result").innerHTML = 'Min value is: ' + minValue + '<br>' + 'Max value is: '+ maxValue + '<br>' + 'Sum value is: ' + sumValue + '<br>' + 'Product value is: ' + productValue + '<br>' + 'Mean value is: ' +   meanValue; 
}

function clearAnswer(){
    document.getElementById("result").innerHTML = '';
    document.getElementById("qty").value = '';
}

<h1> Problem JavaScript</h1> Enter 5 numbers with spaces in between each:
<input type="text" id="qty">  
<input type="button" id="go" value="Calculate" onclick="calculate()">
<button type="reset" id="reset" onclick="clearAnswer()">Clear</button>
<div id="result"></div> 

Answer 1

I tried $.trim but couldn't figure out how to get that to work.

如果您使用jquery trim然后确保您首先包含 jquery 库。

改变

var numArray = numInput.split(" ").map(function(t) {
return parseInt(t);
});

到

var numArray = $.trim( numInput ).split(" ").map(function(t) {
  return parseInt(t);
});

或者简单地

var numInput = $.trim( document.getElementById("qty").value ); 

首先使用$.trim() trim numInput

编辑:

你真的不需要只使用jquery来使用trim函数，javascript本身有trim方法，您可以使用。