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Javascript 给定数字和13之间的差异显示-我输入的每个数字为13_Javascript - Fatal编程技术网

Javascript 给定数字和13之间的差异显示-我输入的每个数字为13

Javascript 给定数字和13之间的差异显示-我输入的每个数字为13,javascript,Javascript,代码: XXXXXXXXXX const nr1=document.getElementById(“nr1”).value; 常数nr2=13; const button=document.getElementById(“计算”); 函数计算(){ 如果(nr1-nr2>=13){ document.getElementById(“结果”).innerHTML=(nr1-nr2)*2; } 否则{ document.getElementById(“结果”).innerHTML=nr1-nr

代码:


XXXXXXXXXX

const nr1=document.getElementById(“nr1”).value; 常数nr2=13; const button=document.getElementById(“计算”); 函数计算(){ 如果(nr1-nr2>=13){ document.getElementById(“结果”).innerHTML=(nr1-nr2)*2; } 否则{ document.getElementById(“结果”).innerHTML=nr1-nr2; } }
用户输入的值存储在DOM load中,此时该值为空。换句话说,缓存输入,而不是它的
。输入必须转换为数字才能执行算术运算

const
nr2=13,
nr1=document.getElementById(“nr1”),
按钮=document.getElementById(“计算”);
函数计算(){
设n1=数字(nr1.value);//转换为数字。请参阅浏览器支持
如果(n1-nr2>=13){
document.getElementById(“结果”).innerHTML=(n1-nr2)*2;
}否则{
document.getElementById(“结果”).innerHTML=n1-nr2;
}
}


常量nr1…
放入函数是的,在函数内部!也许将其显式转换为整数会使代码更容易阅读/理解谢谢。现在可以用了,谢谢。真的很有帮助!