javascript Find the position of a character in an array by half (ordered list)_javascript skills

复制代码 代码如下:

/**
* Find the position of the character in the array (ordered list)
* @param array The retrieved array
* @param x The character to be found
* @type int
* @returns The position of the character in the array. If not found, return -1
*/

function binarySearch(array,x){
var lowPoint=1;
var higPoint=array.length;
var returnValue=-1;
var midPoint;
var found=false;
while ((lowPoint<=higPoint)&&(!found)){
midPoint=Math.ceil((lowPoint higPoint)/2);
//console.log(lowPoint "====" midPoint "====" higPoint);
if(x>array[midPoint-1]){
lowPoint=midPoint 1;
}
else if(xhigPoint= midPoint-1;
}
else if(x=array[midPoint-1]){
found=true;
}

}
if(found){
returnValue=midPoint;
}
return returnValue;
}
/*var array2=[1,2,3,4,5,6,7,8,9,100,109];*/
var array2=['a','b','c','d','e','f','g'];
console.log(binarySearch(array2,'c'));