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function isPalindrome(x) { if(x<0||(x!=0&&x%10===0)) return false let temp=x,res=0 while(temp){ res=res*10+temp%10 temp=Math.floor(temp/10) } return res===x }; console.log( isPalindrome(0)) for( let i=0;i<10000;i++){ if(isPalindrome(i)){ console.log(i); } }