JS_SameValue 编辑

This article covers features introduced in SpiderMonkey 1.8.1

Determines if two jsvals are the same, as determined by the SameValue algorithm in ECMAScript 262, 5th edition.

SameValue slightly differs from strict equality (===) in that +0 and -0 are not the same and in that NaN is the same as NaN. The SameValue algorithm is equivalent to the following JavaScript:

function SameValue(v1, v2)
{
  if (v1 === 0 && v2 === 0)
    return 1 / v1 === 1 / v2;
  if (v1 !== v1 && v2 !== v2)
    return true;
  return v1 === v2;
}

Syntax

// Added in SpiderMonkey 45

bool
JS_SameValue(JSContext *cx, JS::Handle<JS::Value> v1, JS::Handle<JS::Value> v2,
             bool *same);

// Obsolete since JSAPI 39

bool
JS_SameValue(JSContext *cx, jsval v1, jsval v2, bool *same);

Description

JS_SameValue determines whether two values are the same, returning true or false accordingly. This method is infallible.

See Also

• MXR ID Search for JS_SameValue
• JS_StrictlyEqual
• JS_LooselyEqual
• bug 1132045 -- use handle